Valadao graduated from Hanford High School in 1995. From 1996 to 1998 he attended the College of the Sequoias in Visalia as a part-time student but did not graduate.

In August 2011 Valadao announced that he would seek the Republican nomination for California’s 21st congressional district. The district had previously been the 20th District, represented by four-term Democrat Jim Costa, but redistricting had shifted most of the district’s share of Fresno to the new 16th District, and Costa sought reelection there.

Valadao was born and raised in Hanford, California. His parents are Portuguese immigrants; his father grew up on the Azores Islands. In a 2013 interview Valadao said his parents were initially registered Democrats but later switched to the Republican Party.

In 2013 Valadao was one of 15 House Republicans to vote against a Republican-backed bill to make deep cuts in food stamp spending.

Valadao ran for reelection in November 2014. His challengers were Democrat Amanda Renteria, a former political aide to Dianne Feinstein and Debbie Stabenow, and John Hernandez, the Democratic nominee Valadao defeated in 2012. In the June 3 primary Valadao finished first once again with 63% of the vote, and received majorities of 60% or higher in every county except for Kern. In the November 4 general election he was reelected with 58% of the vote.

In 2014, President Obama blamed a drought that California began experiencing in 2011 on global warming. According to The Hill, Valadao was among Republican candidates in three swing districts in California who said “climate change has nothing to do with the drought.” Valadao argued that regulations by the Obama administration had worsened the drought.

In August 2014 he broke ranks with the Republican Party and voted against a bill that would have dismantled the Deferred Action for Childhood Arrivals (DACA) program.

In August 2014 the United States Chamber of Commerce awarded Valadao its Spirit of Enterprise Award. He won the same award again in 2016.

Valadao ran for reelection to a third term in 2016. His first challenger was Democrat Daniel Parra, the Mayor pro tem of Fowler, California. Another Democratic challenger was Connie Perez, an accountant in Pasadena, California, who grew up in Tulare, but due to issues regarding her residency outside of the district, as well as an alleged recent change in party affiliation, Perez dropped out less than a month after announcing her candidacy. In January 2016 Emilio Huerta, son of United Farm Workers co-founder Dolores Huerta, announced his candidacy in the race as a Democrat. In the June 7 primary Valadao finished first with 54% of the vote and Huerta finished second with 24.2%. In the general election Valadao was reelected with 56.7% of the vote to Huerta’s 43.3%.

After Donald Trump became the presumptive Republican presidential nominee in May 2016, Valadao said he would support his candidacy. He rescinded his support in June 2016, declining to endorse Trump and saying he could not support a candidate who “denigrates people based on their ethnicity, religion, or disabilities.”

In 2016, Valadao voted for a measure that banned discrimination against LGBT employees by federal contractors. In 2015, Valadao did not sign a Supreme Court brief co-signed by hundreds of conservative politicians in favor of same-sex marriage.

Marijuana legalization advocacy group NORML gave Valadao a “D” grade in 2016 for his voting history on cannabis-related causes.

In February 2017, Valadao voted against a resolution that would have directed the House to request ten years of Trump’s tax returns, which would then have been reviewed by the House Ways and Means Committee in a closed session.

Valadao favored repealing the Affordable Care Act. On May 4, 2017, he voted to repeal it and to pass the American Health Care Act (AHCA). He was one of three co-sponsors of a last minute amendment that added $8 billion to fund high risk pools for patients with pre-existing conditions. The revised version of AHCA allowed states to get waivers to allow insurers to charge individuals with preexisting conditions more if the individual has had a gap in insurance coverage.

In June 2017 Valadao and Jeff Denham (CA-10) introduced the Assessing Critical Care Efforts to Strengthen Services (ACCESS) Act. It would correct California’s Medicaid reimbursement method in order to encourage physicians to operate in the Central Valley and to ensure patient access to doctors and specialists.

In July 2017, Valadao and five other members of Congress introduced the Training the Next Generation of Primary Care Doctors Act of 2017, which would reauthorize the Teaching Health Center Graduate Medical Education (THCGME) Program. It would expand existing programs at health centers and establish new teaching health centers.

On February 23, 2017, Valadao called for a bipartisan solution to the U.S. immigration system. Later in 2017 he and nine other lawmakers wrote to Speaker of the House Paul Ryan asking for legislation to address DACA’s future.

In December 2017 Valadao voted in favor of the Tax Cuts and Jobs Act.

In January 2017 Valadao introduced H.R. 299, the Blue Water Navy Vietnam Veterans Act, “to grant presumptive Agent Orange exposure status to U.S. service members who served in the territorial seas of Vietnam during the Vietnam War. This would enable eligible veterans to receive expedited consideration for Veterans Affairs (VA) benefits if they suffer from any of the diseases the U.S. Government has linked to Agent Orange.” In August 2017 Valadao and Representative Joe Courtney sent a letter urging the Secretary of the U.S. Department of Veterans Affairs to ensure that Blue Water Navy Vietnam Veterans have access to medical care from the VA.

In 2017, Valadao was blacklisted by Azerbaijan for taking part in a visit to Armenia and a disputed, breakaway region of Nagorno-Karabakh, which is populated and governed by ethnic Armenians.

In March 2018 Valadao, a general partner of Triple V Dairy, was named in two lawsuits against the dairy for defaulting on almost $9 million in loans and for failing to pay a supplier. In June 2018 a bank seized the dairy and sold it off to pay its debts. Valadao said, “Like so many family dairy farms across the country, burdensome government regulations made it impossible for the operation to remain open.” After a lawsuit in 2019, Valadao agreed to pay $325,000 to former employees who sued for being denied breaks, minimum wage and overtime pay. The settlement was not paid due to Valadao filing for bankruptcy.

In 2018 Valadao was initially set to face Huerta again in a rematch, with Huerta announcing his bid in May 2017. But in March 2018 Huerta suspended his campaign for lack of funds. After Huerta’s withdrawal, engineer T. J. Cox of Fresno announced that he would challenge Valadao. Cox had previously announced a challenge to Republican Congressman Jeff Denham in the 10th district before switching to Valadao’s seat.

Valadao declared victory on November 6 after the Associated Press initially called the race in his favor, but the counting of mail-in ballots gave Cox a very narrow lead. Cox officially won the race on November 28, and Valadao conceded on December 6. The final count showed that Cox won by 862 votes. It was one of the last U.S. House races to be decided in the 2018 cycle.

In June 2018 Valadao released a statement about the Department of Justice’s “zero tolerance” policy, which involved separating children and parents at the Mexican border. “The substantial increase of minors at our southern border is both a humanitarian and national security crisis,” he wrote. “While we must work towards a solution that reduces the occurrence of illegal border crossings, it is unacceptable to separate young children from their parents. This is exactly why passage of a compromise solution, such as that being discussed in Congress right now, is absolutely necessary.”

Valadao has criticized the Trump administration’s imposition of tariffs against Chinese steel and aluminum imports, which prompted China to impose retaliatory tariffs on a range of U.S. agriculture products. In May 2018 he sent a letter to United States Trade Representative Robert Lighthizer expressing concern over the tariffs’ impact on the Central Valley’s economy, writing, “Not only do the proposed tariffs fail to adequately remedy China’s unfair practices, such tariffs seriously jeopardize our farmers’ access to export markets, which accounts for roughly twenty percent of their production.”

Valadao lives in Hanford with his wife, Terra, and their three children. Valadao consistently ranked as the poorest member of Congress during his tenure, with over $17.5 million in debt in 2018, mainly loans to his family’s dairy farm.

Valadao is running to reclaim his former seat in 2020.