Lapid was born in Tel Aviv. His father was journalist and politician Yosef “Tommy” Lapid, who served as Justice Minister, and his mother is novelist and playwright Shulamit (Giladi) Lapid. He has a sister, Merav, who is a clinical psychologist. Another sister, Michal, died in a car accident in 1984. Both of his grandmothers were alive when his parents moved to Israel. His great-grandmother Hermione Lampel was arrested in Serbia and sent to Auschwitz, where she was murdered in a gas chamber.

In 1988, at age 25, Lapid was appointed editor of Yedioth Tel Aviv, a local newspaper published by the Yedioth Ahronoth group. In 1991, he began writing a weekly column in a nationwide newspaper’s weekend supplement—first for Maariv, and later for its competitor, Yedioth Ahronoth. His column’s name, “Where’s the Money?”, became his political slogan decades later.

From 1989 to 2010, Lapid wrote and published several books, spanning a variety of genres. His first was a thriller, of which he has published three more; the others include two children’s books, two novels, and a collection of his newspaper columns. In addition, he wrote a drama series, War Room, that aired on Channel 2 in 2004.

In 1994, Lapid started on TV, hosting the leading Friday evening talk show on Israel TV’s Channel 1. That same year, he had an acting role in an Israeli film, Song of The Siren. He next hosted a talk show on TV’s Channel 3. From 1999 to 2012, Lapid hosted a current affairs talk show on Channel 2.

In January 2008, Lapid was the host of Ulpan Shishi (Friday Studio), Channel 2’s Friday night news magazine. That year, the Cameri Theater performed his first play, The Right Age for Love.

On 8 January 2012 Lapid announced that he would be leaving journalism in order to enter politics. On 30 April he formally registered his party, “Yesh Atid” (Hebrew: יש עתיד‎, lit., “There’s a Future”). The move was timed to coincide with the general expectation in Israel for early elections to be held in the early fall of 2012.

A few days after Yesh Atid’s registration, in a surprise move, Israeli prime minister Benjamin Netanyahu formed a national unity government. It was then thought that Lapid’s party would have to wait until late 2013 before it could participate in national elections. But in October 2012, following the departure of Kadima from Netanyahu’s coalition over how to implement a Supreme Court decision ending the exemption from the military draft for the ultra-Orthodox, Netanyahu announced that elections would take place in late January 2013, affording Yesh Atid its first opportunity to run. In November 2012, Yesh Atid was polling an average of 11.6%, or 13–14 seats in the 120-seat Knesset. The results of the January election showed the party winning an unexpected 19 seats, making Yesh Atid the second-largest party in the 19th Knesset.

In January 2012, controversy arose after Lapid was admitted by Bar-Ilan University into a doctorate program, studying towards a PhD in hermeneutics. This was in violation of rules stating that all doctoral candidates must hold at minimum a bachelor’s degree. Lapid, who had failed to complete high school, was admitted to the university based on his extra-academic credentials and career in journalism and writing. After the Knesset Education Committee launched an investigation, the Council for Higher Education canceled the program, under which Lapid was admitted, which had allowed students without a BA to study towards a doctorate.

In September 2013, the Israeli edition of Forbes magazine estimated Lapid’s net worth at 22 million shekels.

Lapid was named Israel’s finance minister on 15 March 2013. Only nine months later, a survey was published showing a continuing trend of decreasing popularity, with 75% of those polled claiming to be disappointed by his performance, and his party achieved only 10 seats in the Knesset, as opposed to the 19 it got at the beginning of the year.

Lapid has said that he would demand a resumption of negotiations between Israel and the Palestinian Authority. His party’s platform calls for an outline of “two states for two peoples”, while maintaining the large Israeli settlement blocs, a united Jerusalem, and ensuring Israel’s safety. In January 2013, just days before the election, Lapid said he wouldn’t join a cabinet that stalled peace talks with the Palestinian Authority, and added that a single country for both Israelis and Palestinians without a peace agreement would endanger Israel’s Jewish character. He said, “We’re not looking for a happy marriage with the Palestinians, but for a divorce agreement we can live with.” As part of a future peace agreement, Lapid said Palestinians would have to recognize that the large West Bank settlement blocs of Ariel, Gush Etzion and Ma’aleh Adumim would remain within the State of Israel. According to Lapid, only granting Palestinians their own state could end the conflict and Jews and Arabs should live apart in two states, while Jerusalem should remain undivided under Israeli rule.

In 2013, when Yesh Atid sat in the government, Lapid pushed for increased public transportation on Shabbat, as opposed to the current law that mandates most public transportation shut down.

During the 2013 election campaign, Lapid spoke of “equal shares of the burden” for all Israeli citizens. He said he would work to see all Israeli citizens, including the thousands of Haredim, who had up until that point been exempt from most civil service, be included in military and civil service. On 27 May 2013, Lapid threatened to topple the government unless ultra-Orthodox would be subject to criminal sanctions for draft-dodging. In the view of some Haredim, Lapid’s plan represents a “spiritual holocaust”, as they believe that their Jewish studies are what upholds Israel. Some Haredim have declared that even at the risk of being criminals, they will continue in their Jewish studies and refuse to enlist or perform civilian service. Lapid denied that he was seeking to destroy the Haredi way of life, saying: “Not one of us wishes, Heaven forbid, to force hiloniyut [secularism] on you or to impose our version of Israeli identity. This state was established so that Jews could be Jews, and live as Jews, without having to fear anyone.”

The Lapidomator Facebook status generator of a unique text was written by a team of Israeli programmers in July 2013. It has generated new Lapid statuses of every word, and Mako demonstrated three different statuses generated from the words “Lapidomator”, “Yair Lapid”, and “Bullshit”.

In May 2013, Lapid ranked first on the list of the “Most Influential Jews in the World” by The Jerusalem Post.

On 2 December 2014, Netanyahu fired Lapid as finance minister.

In June 2015, after the March 2015 elections, Lapid visited the United States, and after an hour-long interview, American journalist Jeffrey Goldberg wrote, “Lapid is a leader of the great mass of disillusioned centrists in Israeli politics. He could conceivably be prime minister one day, assuming Benjamin Netanyahu, in whose previous cabinet he served, ever stops being prime minister. Now functioning as a kind of shadow foreign minister, Lapid argues that Israel must seize the diplomatic initiative with the Palestinians if it is to continue existing as a Jewish-majority democracy, and he is proposing a regional summit somewhat along the lines of the earlier Arab Peace Initiative. Lapid is not a left-winger—he has a particular sort of contempt for the Israeli left, born of the belief that leftists do not recognize the nature of the region in which they live. But he is also for territorial compromise as a political and moral necessity, and he sees Netanyahu leading Israel inexorably toward the abyss.”

In September 2015, Lapid laid out his diplomatic vision in a major speech at Bar Ilan University in which he said, “Israel’s strategic goal needs to be a regional agreement that will lead to full and normal relations with the Arab world and the creation of a demilitarized independent Palestinian state alongside Israel. That’s where Israel needs to head. Separation from the Palestinians with strict security measures will save the Jewish character of the state.”

Additionally, Lapid strongly supports instituting a civil marriage track in Israel. Currently, marriage and divorce for Jews are controlled by the Chief Rabbinate. The Chief Rabbinate will not officiate marriages between Jews and non-Jews, and some Israelis from the Soviet Union—who are not Jewish according to Jewish law—cannot marry in Israel. Although Israel recognizes civil marriages that are performed abroad, there is no mechanism for performing civil marriage in Israel. In 2015, under Lapid’s leadership, Yesh Atid championed a bill to institute civil marriage, but the bill was defeated in the Knesset, with 50 votes against and 39 in favor.

Under Lapid, Yesh Atid claims to spearhead the fight against corruption in Israel. The “Nachshon Plan”, unveiled in 2017, stipulates that any person found guilty of corruption will be banned from serving in public office. To prevent political bribery, it also abolishes “coalition funds”.’

Lapid supports recognition of Israeli sovereignty over the Golan Heights. He noted in 2017 that with Iran attempting to establish a foothold in Syria, Israel cannot be expected to relinquish the Golan Heights.

When Netanyahu walked back his promise to Diaspora Jews in 2017 to expand prayer at the Western Wall, Lapid slammed the decision, saying that the Israeli government alienated “senators, congressmen, the majority of the pro-Israel lobby, major donors, the people we turn to when we need help ensuring that Israel will get advanced weapons, that the military assistance will increase, that there will be sanctions on Iran”. He implored American Jews to “not give up on us. We have no intention of giving up on you. We are one people. It might take time. It might take elections. But in a democracy, the majority decides, and the majority in Israel want us to be one nation.” Lapid asserts that it is Israel’s responsibility to recognize all streams of Judaism, including streams which don’t follow Jewish Law.

In February 2018, Polish Prime Minister Mateusz Morawiecki said “there were Jewish perpetrators” of the Holocaust, “not only German perpetrators”. Lapid condemned Morawiecki’s words: “The perpetrators are not the victims. The Jewish state will not allow the murdered to be blamed for their own murder.”

The Lapidomator was covered widely in the media, and continued to be active after Lapid ceased to be Finance Minister. On 7 November 2018, MK Tamar Zandberg complained about the empty seats of Lapid and Ofer Shelah, who were absent during the vote on public transportation on Saturdays, and the Lapidomator generated an adequate status.