John Mulaney: Baby J is a 2023 stand-up comedy film written by and starring John Mulaney. It was recorded in February 2023 at the Boston Symphony Hall and was released by Netflix on April 25, 2023. It is Mulaney's fifth stand-up special and was released five years after his fourth, Kid Gorgeous at Radio City (2018). The special consists of Mulaney recollecting his life experiences and escapades surrounding his drug addiction, including his intervention and subsequent rehabilitation.

John Edmund Mulaney is an American stand-up comedian, actor, writer, and producer. Born and raised in Chicago, Illinois, Mulaney first rose to prominence for his work as a writer for the NBC sketch comedy series Saturday Night Live from 2008 to 2013, where he contributed to numerous sketches and characters, including Stefon, a recurring character that he and Bill Hader co-created. Since his departure from SNL, Mulaney has hosted it several times, becoming a member of the SNL Five Timers Club in 2022.