Bill Hader is an American actor, writer, comedian and repertory player on Saturday Night Live. He is also known for playing noted supporting roles in numerous comedy films.

Hader's comedic skills led him to perform at the Los Angeles chapter of the famed Second City, a comedy troupe that has been a training ground for many SNL cast members since the 1970s. He also performed at iO West in Los Angeles. During his time at Second City and iO West, Hader worked as a production assistant on the DVD Empire of Dreams: The Story of the Star Wars Trilogy and Collateral Damage, as well as an assistant on VH1's The Surreal Life. Prior to SNL, Hader was perhaps most known for his work as a "field agent" on MTV's Punk'd.

Hader was "discovered" by Megan Mullallyof Will & Grace while working with the Los Angeles-based comedy troupe "Animals from the Future". Mullally brought him to the attention of SNL producer Lorne Michaels. Hader was hired as a "featured player" and made his debut on the show on October 1, 2005 (along with fellow newcomer Andy Samberg). His first role was as a psychologist giving his views about life and death during the emergency landing of Jet Blue Flight 292. Hader is known for his impressions of famous people, such as Vincent Price in the Variety Vault sketches and Al Pacino

Hader is going into his 4th season on SNL and, along with Andy Samberg, Kenan Thompson and Casey Wilson, is one of four SNL cast members who was born after the show's premiere in 1975. Samberg, Thompson, and Hader were all born in 1978, and Wilson was born in 1980.

Hader has said he did impressions of teachers and friends when he was growing up, but did not do impressions of famous people until his Saturday Night Live audition. His Al Pacinoimpression came after watching the actor's Emmy acceptance speech for Angels in America. Hader's Vincent Price impression came from his love of Price's Edgar Allan Poe films, such as The Fall of the House of Usher. His Peter O'tooleimpression came partly from O'Toole in My Favorite Year and Jack Lemmon's drunken Prince Hapnick from The Great Race.

He first appeared alongside Owen Wilsonand Matt Dillonin You, Me and Dupree. Since then he's had a wide range of roles such as Katherine Heigl's editor at E! in Knocked Up, the acid-taking mechanic Dave in Hot Rod, a recumbent biker in The Brothers Solomon and, most famously, as Officer Slater in the Judd Apatow produced Superbad. His role in Superbad helped boost his public repertoire and allowed him to appear on mainstream programs like TRL, The Tonight Show, and even presenting at MTV's Video Music Awards.

Hader appeared in two other Apatow projects: Forgetting Sarah Marshall and Pineapple Express (with Seth Rogen. He also appeared alongside Ben Stiller, Jack Black Robert Downey Jr, Matthew McConaughey, Steve Coogan and Nick Nolte in Tropic Thunder. He will team back up with Superbad director Greg Mottola for the film Adventureland, which also features fellow SNLer Kristen Wiig. In addition to these films, Hader has also made several short films, including Back in the Day, Sounds Good to Me: Remastering the Sting, and The Jeannie Tate Show with SNL writer Liz Cackowski and wife Maggie Carey.