[3] In 2010, Zeldin ran in the New York State Senate's 3rd District, challenging Democratic incumbent Brian X. Foley.

[20][21] Zeldin did not vote on the NY SAFE Act, a gun control bill that passed the New York State Senate on January 14, 2013,[22] and later became law.

[25] In February 2014, Zeldin introduced a bill that sought to halt implementation of the Common Core curriculum for three years.

[26] In March 2014, Zeldin voted against the New York Dream Act, which would allow undocumented students who meet in-state tuition requirements to obtain financial aid to study at the university level.

In the November 8 general election, he faced Democratic nominee Anna Throne-Holst, a member of the Southampton Town Board.

In the November general election his chief opponent was Democratic nominee Perry Gershon, who also had the endorsement of the Working Families Party.

[39] Zeldin's 2018 campaign featured fundraisers with Breitbart News founder Steve Bannon[40] and Sebastian Gorka.

[58][59] In June 2021, Republican state chair Nick Langworthy named Zeldin the party's "presumed nominee" after he earned 85% of a straw poll vote of county leaders.

[69] Zeldin's preferred pick for lieutenant governor, retired NYPD Deputy Inspector Alison Esposito, ran unopposed and also received the state party's designation.

[70] Zeldin faced Rob Astorino, Andrew Giuliani, and Harry Wilson in the 2022 Republican gubernatorial primary[71] and was declared the winner on June 29, 2022.

A man, later identified as David Jakubonis,[73] got on the stage while Zeldin was giving a speech and attacked him with a pointed plastic key chain intended to be used for self-defense.

[78] Monroe County district attorney Sandra Doorley, who is also a co-chair of Zeldin's campaign,[79] recused herself from the case because she was at the event.

[86] On January 29, Supreme Court Justice Brett Kavanaugh swore Zeldin into office as the 17th Administrator of the Environmental Protection Agency.

[93][94] Zeldin opposes abortion and has said that regardless of what the Supreme Court decides on Roe v. Wade, "nothing changes in the state of New York".

[98][99] In July 2015, Zeldin attached an amendment to the Student Success Act to allow states to opt out of Common Core without penalty.

[102] During his confirmation hearing for EPA Director, Zeldin stated that climate change is a real issue and needs to be addressed.

[111] In January 2016, the New York Post reported that Zeldin was a no-show in 2015 at 12 of 18 House Committee on Foreign Affairs hearings that dealt specifically with ISIL and with Syria.

[8] In 2016, he spoke in support of the anti-Boycott, Divestment and Sanctions (BDS) legislation that passed the New York State Senate.

[117] Zeldin spoke highly of the Abraham Accords and nominated Jared Kushner and Avi Berkowitz for a Nobel Peace Prize for their work on the agreement.

[133] Zeldin voted against both the bipartisan Infrastructure Investment and Jobs Act on July 1, 2021,[134] and the Senate amendment to it on November 5, 2021.

[135][136] In April 2016, Zeldin introduced legislation to prevent the federal government's sale of Plum Island to the highest bidder.

[141] Critics of the measure said it would enable people to violate same-sex couples' and their children's legal rights by discriminating against them.

[161] Zeldin said the investigations were launched with "insufficient intelligence and biased motivations", with surveillance warrants for Trump campaign staffers obtained in "deeply flawed and questionable" ways.

He instructed the House to withhold his pay until the shutdown ended, saying: "It's crazy to me that members of Congress get paid while other federal employees do not.

"[166][167] After Trump lost the 2020 presidential election and made false claims of fraud, Zeldin was one of 126 Republican members of the House of Representatives to sign an amicus brief in support of Texas v. Pennsylvania, a lawsuit filed at the United States Supreme Court contesting the results of the election, in which Biden defeated Trump.

[168] The Supreme Court declined to hear the case on the basis that Texas lacked standing under Article III of the Constitution to challenge the results of an election held by another state.

[173][174][175][176] He disavowed the violence and argued with protesters at his Patchogue office who linked his espousal of election fraud conspiracy theories to the Capitol attack and called on him to resign.

[181] In February 2016 he proposed federal legislation to fund a three-year, $25-million nationwide veterans' peer-support program modeled on one he helped establish while in the New York State Senate.

His grandfather, Rabbi Abraham Jacob "Jack" Zeldin, founded Farmingdale Jewish Center, a Conservative synagogue.

[187] In 2023, Zeldin launched Leadership America Needs, a PAC aimed at increasing Republican turnout among the young and voters of color.