Kirby Howell-Baptiste was born and raised in London, England. She first enrolled in acting classes at the Anna Scher Theatre (now known as the Young Actors Theatre) when she was 12.
Upon leaving secondary school, Kirby starred in Echoic, a devised West End play with the Talawa Theatre Company, Britain's foremost Black-led Theatre company. Kirby's passion then led her to study acting at the East 15 Acting School, and then to Los Angeles, to study at the Lee Strasberg Theatre and Film Institute.
Since moving to Los Angeles, Kirby has appeared in several television series including House of Lies (Showtime), Comedy Bang! Bang! (IFC) and Bajillion Dollar Properties (Seeso). She recurs as “Beth” in the Judd Apatow/Lesley Arfin/Paul Rust series, LOVE (Netflix) and was a series regular on the ABC show Downward Dog. Kirby will next be seen in Bill Hader’s HBO series Barry, which premieres in March 2018.