Jimmy Kimmel has officially entered his “grandpa era.” The late-night host, 57, revealed during his May 20 monologue that his daughter Katie, 33, has given birth to her first child—a baby girl named Patti.

The joyful news explained his show’s unexpected absence the previous night, as Patti was born right around the time they typically film.

Kimmel shared that baby Patti is healthy and doing well. Her middle name, Joan, honors Kimmel’s mother. He described the delivery room as being filled with supportive family members, calling it an “army of family.”

He also addressed the canceled May 19 taping, apologizing to the missed studio audience and guest Seth Rogen. Ever the comedian, Kimmel joked that Rogen was “totally high” when he gave him the last-minute call.

Katie is Kimmel’s daughter from his previous marriage to Gina Maddy, with whom he also shares son Kevin, 31. With his current wife, Molly McNearney—also a producer on his show—he has two younger children: Jane, 10, and Billy, 8.

Kimmel took a heartfelt moment to reflect on his son Billy’s health journey. Born with a congenital heart defect, Billy underwent three open-heart surgeries. After the latest procedure in 2024, Kimmel posted on Instagram celebrating Billy’s successful recovery and new heart valve.

Joking about his new grandparent role, Kimmel mused over what exactly a grandfather does, saying he needs to come up with something “weird” to teach his granddaughter. He also noted how daunting the world feels today for kids growing up amid climate change, AI, and political tension.