Peter Gosselin Fitzgerald (born October 20, 1960) is a retired American lawyer and politician who served as a United States Senator from Illinois.

Fitzgerald defeated Democratic incumbent Carol Moseley Braun in 1998, becoming the first Republican to win a U.S. Senate race in Illinois since Charles Percy twenty years earlier.

Fitzgerald had two major moments in the spotlight in the Senate, the first in 2000 when he filibustered a massive federal spending bill because it included funds for the Lincoln Presidential Library in Springfield.

Standing alone out of all members of the U.S. Senate, Fitzgerald delivered a speech, "Who will bail out the American taxpayer",[10] arguing that the airlines would simply go through the money and remain financially unstable.

He insisted on the appointment of an out-of-state U.S. Attorney, Patrick Fitzgerald (unrelated[11]) to investigate corruption in the Illinois state government.

Several indictments resulted, including that of former Republican Governor George Ryan, who was eventually convicted of several criminal abuses of authority, and Democratic Governor Rod Blagojevich, who many years later was convicted of attempting to sell the Senate seat vacated by Fitzgerald's successor and future President Barack Obama.

[12][13] When the Republican establishment made clear that they would not support him for reelection, Fitzgerald announced he would retire at the end of his current term.

However, Ryan was later pressured by the Illinois Republican Party to withdraw because of publicity received from the contents of his previously-sealed divorce case.

It has been stated that Fitzgerald, who was popular among independents, stood the best chance of retaining the seat and defeating Obama, who went on to win the presidential election just four years later.

[13] During his final months in office, Fox News ran an op-ed on Fitzgerald, "Retiring Senator Stood Up for Principles.