John Mahoney, the beloved dad on "Frasier," has died in Chicago ... TMZ has learned.

According to John's publicist ... he passed away Sunday in hospice care.

The British-born actor famously played Martin Crane, the father of Kelsey Grammer and David Hyde Pierce's characters, for 11 seasons of "Frasier."

John most recently had a recurring role in "Hot in Cleveland." Besides his TV success, John was in tons of movies -- like 'American President,' "Say Anything..." and "Eight Men Out" -- during more than 30 years in show biz.

He was my father. I loved him. pic.twitter.com/3mGcyEMxoy @KelseyGrammer

He won a SAG Award in 2000 for "Frasier" -- and was nominated for 2 Emmys and 2 Golden Globes. John was also active in theater, and won a Tony in 1986.

Play video content JULY 2010 TMZ.com

John was 77.