Bill -- a musician best known for being in the group The Hudson Brothers -- married Oliver's mother, Goldie Hawn, in 1976. The two divorced in 1980. The Scream Queens actor and Kate were raised by Goldie's longtime boyfriend, actor Kurt Russell.
Kate paid tribute to Kurt on her own Instagram on Sunday, with this adorable black-and-white picture. "Pa, just simply..... Thank you. Happy Father’s Day. I love you to the moon and back. #HappyFathersDay."
Kate, 36, has slammed Bill in the past, telling Vanity Fair in 2000, "[Bill] doesn't know me from a hole in the wall. But I don't care. I have a dad [Kurt]. The bottom line is, you call your kids on their f**king birthday. I'm glad I had a dad who was there on my birthday."