Ian Brennan (born April 23, 1978) is an American screenwriter, director and actor. He is known for his work on the American television shows Glee, Scream Queens and The Politician.
Brennan lives in both New York City and Los Angeles. He married actress Trilby Glover in September 2016 and the couple have two children, Blaise (born in April 2016) and Juno (born in August 2018).
Brennan is the son of John and Charman Brennan. He is Irish Catholic and his father was a Paulist priest. Brennan spent four years at Prospect High School in Mount Prospect, Illinois during the mid-1990s, and was a member of the school show choir, which he did not find particularly enjoyable. He was friends with actress Jennifer Morrison. Brennan aspired to be an actor, and as his high school musical director was also the show choir director, he joined the choir to enhance his chance of being cast in musical productions. Brennan credits his high school theatre director John Marquette for inspiring him to act. The character Will Schuester in Glee is partially based on Marquette. Brennan went on to study theatre at Loyola University Chicago. He graduated in 2000, and acted for a time in Chicago, studying at The Second City Training Center and working with the Steppenwolf and Goodman Theatres, before moving to New York City to continue his acting career. He has performed in off-Broadway plays at the Vineyard, Playwrights Horizons and MCC Theatres. His early writing experience was limited to sketch pieces in high school and college plays he describes as "terrible".