Jeffrey David Klein (born July 10, 1960) is an American politician and a member of the Democratic Party.

He represented the New York State Senate's 34th District, serving parts of Bronx and Westchester Counties from 2005 to 2018.

Prior to running for the Senate, Klein was reported to be considering a race for New York Attorney General in 2006, but did not do so because Andrew Cuomo and Jeanine Pirro were competing for that position.

[citation needed] After considering a race for New York Attorney General, Klein opted to run for re-election.

Yet not long after the Senate Democrats' momentous victory, on December 4, 2012, Klein and the Republican Leadership announced a power-sharing agreement between the IDC and the G.O.P.

[11] Klein was a prime sponsor of the 2013 New York Secure Ammunition and Firearms Enforcement Act (NY SAFE Act), which enacted new comprehensive gun control measures statewide in the wake of the Sandy Hook Elementary School shooting in Newtown, Connecticut, and in response to mass shootings nationwide.

[13] Prior to the 2013 state budget negotiations, Klein publicly demanded that New York increase its minimum wage as part of a final agreement.

[14] Klein's support was seen as critical to the measure's success, which will increase New York's minimum wage to $9 per hour by the end of 2015.

[16] Due to pressure from Governor Andrew Cuomo and labor unions, Klein indicated in June 2014 that the IDC would rejoin the Democratic caucus after the November 2014 elections.

[24] Klein and his IDC colleagues rejoined the Senate Democratic Conference in April 2018 at the request of Gov.

[26] The New York Joint Commission on Public Ethics (JCOPE) opened an investigation into the allegation, though by the time it went to an administrative hearing, Klein was no longer in the State Senate, having lost his campaign for reelection.

The findings concluded that the Public Officers Law under which Klein was charged did not apply because the alleged incident appeared to be isolated and did not affect government decision-making.

[40] After leaving the state Senate, Klein became a lobbyist for Mercury Public Affairs, based in New York City.