The Staten Island Republican Party, abbreviated SIGOP, is a regional affiliate of the United States Republican Party for the borough of Staten Island in New York City, New York.

As with all county affiliates of the New York Republican State Committee, the Staten Island Republican Party is governed by the Richmond County Republican Committee, whose chairman is the chairman of the county's party and selected by members of the Committee. The current chairman is Michael Tannousis and his chief operating officer is former chairman Anthony Reinhart.

In the 21st Century, Staten Island has stood apart from the other boroughs of New York City as a conservative and Republican stronghold in an otherwise liberal and progressive Democratic Party-dominated city. As such, the Island's Republican party has had success in borough-wide elections, and has nearly consistently won the island's congressional seat.

In 2008 it was discovered that Vito Fossella, the Representative from New York's 13th congressional district and the only Republican representing New York City, was arrested for a DUI and had a second secret family in Virginia. Fossella declined to seek reelection in 2008. The Staten Island Republican Chairman John Friscia tapped Frank Powers to run for the seat and replace Fossella. However, Powers' son would actively campaign against him, and he would die on the campaign trail just months before the election. As such the party scrambled to nominate Robert A. Straniere, a member of the New York State Assembly, to run, but he would lose to Democrat Michael McMahon who got 60.9% of the vote.

In 2010, Chairman Friscia shocked most of the party and Republican establishment in the city by trying to tap Fossella to run again. The move was opposed by almost every executive within the party, and the Brooklyn Republican Party, who also have a say in the candidate. Additionally, then mayor Rudy Giuliani opposed a Fossella comeback, endorsing Michael G. Grimm who would go on to win the party's primary after Fossella declined to run.

Michael G. Grimm, a former FBI agent that investigated fraud, was an incumbent United States Representative for the 11th District and was indicted of mail fraud and wire fraud for his part in a scheme running a fraudulent health food store. Grimm initially sought to retain his seat, and the Staten Island GOP was seemingly in favor of this, however, he ultimately decided to resign and a special election was called.

The 2015 special election saw Dan Donovan, the incumbent Staten Island District Attorney run unopposed in the Republican primaries. Donovan would defeat Vincent J. Gentile, a member of the New York City Council for the 43rd District (in Brooklyn) with 58.33% of the vote to his 40.11%.

Another special election, this time to replace Donovan as District Attorney saw Michael E. McMahon, a former congressmen who represented the 13th District from 2009 to 2011, seemingly win in the primaries, as the Borough's Republican party offered no candidate themselves. However, shortly before the deadline to become a candidate, Joan Illuzzi, a prosecutor known for the Etan Patz case, cold called the party's chairman to appear on the ballot, and then win the nomination unopposed. Illuzzi was seeking to become the first female district attorney of Staten Island, however, McMahon would win with 55% of the vote to Illuzzi's 45%, ending 11 years of Republican hold on the district attorney's office.