William "Bill" Maher, Jr. (pronounced /ˈmɑr/; born January 20, 1956) is an American stand-up comedian, television host, social and political commentator, and author. Before his current role as the host of HBO's Real Time with Bill Maher, Maher hosted a similar late-night talk show called Politically Incorrect on Comedy Central and later on ABC.

Maher is known for his political satire and sociopolitical commentary. His commentaries target a wide swath of topics: religion, politics, bureaucracies of many kinds, political correctness, the mass media, greed among people and persons in positions of high political and social power, among many others. He supports the legalization of marijuana and gay marriage and serves on the board of PETA. He is also a critic of religion and is an advisory board member of The Reason Project. Maher is number 38 on Comedy Central's 100 greatest stand-ups of all time.

Maher was born in New York City, the son of Julie (née Berman), a nurse, and William Maher, Sr., a network news editor and radio announcer. Maher was raised in his Irish American father's Catholic religion, and did not find out that his mother was Jewish until his teenage years; Maher's family stopped attending church when Maher was thirteen, because of Maher's father's disagreement with the Pope's position on birth control. Maher grew up in River Vale, New Jersey and graduated from Pascack Hills High School in Montvale, New Jersey. He received his Bachelor of Arts in English and History from Cornell University in 1978.