Toomey attended La Salle Academy on scholarship participating in the Close Up Washington civic education program. He graduated as valedictorian of his high school class. He graduated from Harvard College in 1984 with an A.B. in government.

After graduation, Toomey was hired by Chemical Bank where he was involved in currency swap transactions. In 1986, he was hired by Morgan, Grenfell & Co., where he dealt in multiple foreign currencies, interest rates, and currency-related derivatives.

In 1991, Toomey resigned from Morgan, Grenfell after it was acquired by Deutsche Bank. He later said he resigned out of concern that Deutsche Bank would impose a less flexible and entrepreneurial work environment. The same year, Toomey and two younger brothers, Steven and Michael opened Rookie’s Restaurant in Allentown, Pennsylvania.

In 1994, Toomey was elected to Allentown’s newly established Government Study Commission. During his term, he drafted a new charter for the commission requiring a supermajority for any tax increase. Allentown voters approved the charter on April 23, 1996.

In November 1997, Toomey married Kris Ann Duncan. The couple have three children.

In 1998, Toomey ran for the Pennsylvania’s 15th congressional district, based in the Lehigh Valley region after Democratic incumbent U.S. Representative Paul McHale decided to retire. Toomey won the six-candidate Republican primary with 27% of the vote.

Regarding deregulation of the financial services industry, Toomey said in 1999, “The trend in deregulation, beginning in the early 1980s, is one of the biggest reasons for the sustained economic expansion. I would like to see us continue to deregulate on many fronts, including the financial services industry.”

While serving on the House Banking Committee, in 1999 Toomey helped write House Resolution 10, which led to the repeal of parts of the Depression-era Glass-Steagall Act. The repeal of the Act which had regulated the separation of banks and investment firms, allowed for companies that combined banking and investment operations.

In 2001, Toomey proposed a budget that would cut taxes worth $2.2 trillion over ten years, exceeding Bush’s $1.6 trillion plan.

In 2002, Toomey voted in favor of the Iraq Resolution which authorized military action against Iraq.

During Toomey’s tenure in Congress, he supported legislation that would speed up approval of forest-thinning projects in areas at high risk of wildfire, disease, or pest infestation. In 2003, he supported opening the Arctic National Wildlife Refuge to oil drilling and development, opposed implementing the Kyoto Protocol, and opposed legislation that would mandate increased vehicle fuel efficiency standards and provide incentives for alternative fuels.

In accordance with his 1998 pledge not to serve more than three terms in the House, Toomey did not run for reelection in 2004. He decided to challenge incumbent Republican U.S. Senator Arlen Specter in the primary instead.

In 2004, Toomey challenged longtime incumbent Senator Arlen Specter in the Republican primary election. His campaign was aided by $2 million of advertising from the Club for Growth. Toomey’s election campaign theme was that Specter was not a conservative, especially on fiscal issues. Most of the state’s Republican establishment including Pennsylvania’s other U.S. Senator, Rick Santorum, and President George W. Bush supported Specter. Specter won by 1.6 percentage points, about 17,000 votes out of over one million cast.

In 2004, Toomey said he believes society should give special benefits only to couples who meet the “traditional” definition of marriage as “one man, one woman.” He voted in 2004 in support of an amendment to the U.S. Constitution to ban same-sex marriage. In 2015, Toomey disagreed with the Supreme Court decision which found that same-sex marriage bans were unconstitutional.

On April 15, 2009, Toomey announced his intention to again challenge Specter in the 2010 Republican primary.

On April 28, 2009, Specter announced he would switch parties and run as a Democrat, after polls showed him losing to Toomey in the primary. Specter’s withdrawal left Toomey as the front-runner for the 2010 Republican nomination. Both primaries were held on May 18, 2010.

Toomey was the first Lehigh Valley resident to serve as Senator from Pennsylvania since Richard Brodhead in the mid-19th century. He was elected to the United States Senate on November 2, 2010 and his term began on January 3, 2011. He joined the Congressional Hispanic Conference, a caucus of which he was an original member in his days in the House.

Toomey rejects that there is a scientific consensus on climate change. In 2010, he said, “I think it’s clear that [climate change] has happened. The extent to which that has been caused by human activity I think is not as clear. I think that is still very much disputed and has been debated”. In 2011, he voted to limit the Environmental Protection Agency’s ability to regulate greenhouse gas emissions.

In 2010, Toomey supported the repeal of Don’t ask, don’t tell, a policy that banned openly gay or bisexual persons from serving in the military, in a statement made while he was Senator-elect.

In his first term in Congress, Toomey took credit for getting $12 million in earmark spending for businesses in his district. In 2010 he claimed but provided no proof that he eventually ceased getting earmarks as a congressman, when as a Senate candidate he signed the “No Pork” pledge. In December 2011, Toomey and Senator Claire McCaskill (D-MO) introduced the Earmark Elimination Act of 2011. The bill failed and failed again when it was reintroduced in 2014.

Toomey is anti-abortion. While running for Senate in 2010, he said he supports legislation to ban abortions and jail sentences for doctors who perform them. As a senator, Toomey voted for a bill that would have banned abortions after 20 weeks with no exceptions for the health of pregnant women and girls and new limits in cases of rape and incest. In January 2020 Toomey also signed an amicus brief urging the US Supreme Court to overturn several of its past rulings protecting abortion rights, including Roe v. Wade. When he first ran for Congress in 1998, Toomey said he believed abortion should be legal only in the first trimester.

On August 11, 2011, Senate minority leader Mitch McConnell named Toomey to the United States Congress Joint Select Committee on Deficit Reduction. The committee’s duties included composing a package of spending cuts for submission to both Houses of Congress.

In 2011, Toomey sponsored a federal balanced budget amendment. He supported extending unemployment benefits and offsetting the cost with reduced government spending in other areas.

On April 26, 2012, Toomey was selected to succeed Jim DeMint of South Carolina as chairman of the United States Senate Steering Committee, a caucus of several Republican Senators who collaborate on legislation. DeMint had previously expressed his intention to transfer the committee’s chairmanship to a member of the Republican 2010 Senate class.

Toomey was a leading sponsor of the JOBS Act which passed the Senate in March 2012. The Act would reduce costs for businesses that go public by phasing in SEC regulations for “emerging growth companies” over a five-year period. It would also help startup companies raise capital by reducing some SEC regulations.

In 2013, Toomey voted for a point of order opposing a carbon tax or a fee on carbon emissions. In 2015, he voted against the Clean Power Plan.

In 2013, Toomey was one of 18 senators to vote against the bill to reopen the government during the United States government shutdown of 2013. Of his vote, he said: “The one major redeeming aspect of this bill is that it reopens the government… But I cannot support piling hundreds of billions of dollars of debt on current and future generations of Americans without even a sliver of reform to start putting our fiscal house in order.”

In 2013, in response to the Sandy Hook Elementary School shooting, Toomey and Democratic Senator Joe Manchin introduced legislation that would have required a background check for most gun sales. The legislation failed and failed again when it was reintroduced in 2015. In 2016, Toomey voted against a bill that would prohibit gun purchases by people on the no-fly list. Toomey opposed President Obama’s executive orders on gun control as contrary to the constitutional system of checks and balances, but believes Congress should pass background checks. He received nearly $93,000 from gun-rights groups including the National Rifle Association, but earned a poor rating (a “C”) from the NRA after he started championing background check legislation.

In November 2013, Toomey proposed an amendment exempting private religious entities from following the Employment Non-Discrimination Act. The amendment failed. After the bill received the 60 votes required for cloture, Toomey cast his vote in support.

Toomey voted to reauthorize of the Violence Against Women Act in 2013.

In a series of roll-call votes attached to debate about the Keystone pipeline on January 21, 2015, Toomey voted against an amendment offered by Brian Schatz expressing the sense of Congress regarding climate change but in favor of a similar amendment offered by John Hoeven.

In March 2015, Toomey voted for an amendment to establish a deficit-neutral reserve fund to allow employees to earn paid sick time.

Toomey ran for reelection to the Senate in 2016. He was endorsed by the Club for Growth. He was unopposed in the Republican primary and won the general election with 48.9% of the vote, to Democratic nominee Kathleen McGinty’s 47.2% and Libertarian challenger Ed Clifford’s 3.85%.

In September 2016, Toomey was one of 34 senators to sign a letter to United States Secretary of State John Kerry advocating that the United States use “all available tools to dissuade Russia from continuing its airstrikes in Syria” from an Iranian airbase near Hamadan “that are clearly not in our interest” and stating that there should be clear enforcement by the US of the airstrikes violating “a legally binding Security Council Resolution” on Iran.

Toomey has strongly supported increased public spending on charter schools. In 2017, he supported Betsy DeVos as President Trump’s pick for Secretary of Education. At the time of the vote, Toomey had received $60,500 from the DeVos family during his career. There were weekly protests at his office and high numbers of calls/faxes/emails were noted.

In 2017, as Republicans tried to repeal Obamacare Toomey said the independent insurance market was in a “death spiral” because of the ACA. Toomey helped write the Republican bill to repeal Obamacare.

In November 2017, Toomey co-sponsored the Israel Anti-Boycott Act (s. 720), which made it a federal crime for Americans to encourage or participate in boycotts against Israel and Israeli settlements in the West Bank if protesting actions by the Israeli government.

In September 2018, Toomey was among six Republican senators who voted against a $854 billion spending bill meant to avoid another government shutdown. The bill included funding for the departments of Defense, Health and Human Services, Labor and Education.

In February 2018, Toomey said that it was worth discussing whether to impeach justices on the Pennsylvania Supreme Court who had ruled that a gerrymandered congressional map violated the Pennsylvania constitution.

In March 2018, Toomey voted to table a resolution spearheaded by Bernie Sanders, Chris Murphy, and Mike Lee which would have required Trump to withdraw American troops either in or influencing Yemen within the next 30 days unless they were combating Al-Qaeda.

In April 2018, Toomey was one of eight Republican senators to sign a letter to United States Secretary of the Treasury Steve Mnuchin and acting Secretary of State John Sullivan expressing “deep concern” over a report by the United Nations exposing “North Korean sanctions evasion involving Russia and China” and asserting that the findings “demonstrate an elaborate and alarming military-venture between rogue, tyrannical states to avoid United States and international sanctions and inflict terror and death upon thousands of innocent people” while calling it “imperative that the United States provides a swift and appropriate response to the continued use of chemical weapons used by President Assad and his forces, and works to address the shortcomings in sanctions enforcement.”

In January 2018, Toomey was one of 36 Republican senators to sign a letter to Trump requesting that he preserve the North American Free Trade Agreement by modernizing it for the economy of the 21st century.

In November 2018, Toomey was one of 12 Republican senators to sign a letter to Trump requesting that the United States-Mexico-Canada Agreement be submitted to Congress by the end of the month to allow a vote before the end of the year; they were concerned that “passage of the USMCA as negotiated will become significantly more difficult” in the incoming 116th United States Congress.

In February 2019, Toomey was one of 16 senators to vote against legislation preventing a partial government shutdown and containing $1.375 billion for barriers along the U.S.-Mexico border which included 55 miles of fencing.

In March 2019, Toomey was one of 12 Republican senators to cosponsor a resolution that would impose a constitutional amendment limiting the Supreme Court to nine justices. The resolution was introduced after multiple Democratic presidential candidates expressed openness to the idea of expanding the Supreme Court.

Toomey is a strong supporter of banking deregulation. In 2019 The Washington Post reported, “10 of his 17 biggest campaign contributors are financial company officials.”

In February 2019, Toomey was one of 16 senators to vote against legislation preventing a partial government shutdown and containing $1.375 billion for barriers along the U.S.-Mexico border that included 55 miles of fencing. In March 2019, Toomey was one of 12 Republican senators to vote to block Trump’s national emergency declaration that would have granted him access to $3.6 billion in military construction funding to build border barriers.

In December 2019, Toomey said that it was not worth discussing whether to impeach Trump after he allegedly tried to extort the President of Ukraine, Volodymyr Zelensky, by demanding that Zelensky start a criminal investigation of Vice President Joseph Biden or at least falsely announce an investigation was underway of Trump’s false allegation that Biden engaged in corruption in Ukraine. “Where is the crime?” said Toomey at a Republican fundraiser. Earlier Toomey had described Trump’s attempt to force Zelensky to make false allegations about the Democratic presidential candidate as “errors of judgment”. Toomey had harsher words for House Democrats, accusing them of “disgracefully breaking with” bipartisan precedent on impeachment inquiries.

Later that month the House impeached Trump on multiple charges, including abuse of power in the attempted extortion of Zelensky. Even after Trump was impeached Toomey continued to insist that his offenses were “not impeachable” and opposed hearing from any witnesses at Trump’s trial. “We should move as quickly as we can to get this thing over with, get this behind us,” Toomey said, adding, “Even if someone believes that everything John Bolton says is going to confirm what’s charged in these articles, it’s still not impeachable.” (The New York Times reported Bolton had written in his forthcoming book that Trump had told him in August 2019 that he wanted to continue freezing the Ukraine aid until officials there helped with investigations into Democrats, including the Bidens.) Along with all but one of the other Republican senators, Toomey voted against convicting Trump on the two articles for which he had been impeached by the House.

On April 17, 2020, Senate Majority Leader Mitch McConnell appointed Toomey to the COVID-19 Congressional Oversight Commission to oversee the implementation of the CARES Act.

On October 4, 2020, Toomey was reported to be retiring at the conclusion of his term, forgoing a reelection campaign or a run for governor in 2022. He confirmed the report the next day.

In July 2020, Toomey joined fellow Republican Senator Mitt Romney in condemning Trump’s decision to commute Roger Stone’s sentence, saying that while Trump “clearly has the legal and constitutional authority to grant clemency for federal crimes,” commuting Stone’s sentence was a “mistake” due in part to the severity of the charges against him and that “Attorney General Bill Barr stated he thought Mr. Stone’s prosecution was ‘righteous’ and ‘appropriate’ and the sentence he received was ‘fair.'”