'Frasier' Star John Mahoney Leaves Behind $5 Million Estate

John Mahoney, the beloved dad on "Frasier," left behind millions of dollars ... and TMZ's learned there's a long list of potential benefactors.

John's friend, Bernard Dowling, filed legal docs in Cook County, Illinois to open a probate case for his estate. According to docs, obtained by TMZ, John's estate is worth north of $5 million, including around $300k worth of real estate. There are also 38 relatives and friends listed as potential benefactors.

TMZ broke the story ... John died in hospice care back in February. As we first reported ... the official causes of death included brain disease, lung cancer and seizures. He also suffered from kidney disease and diabetes.

John played Kelsey Grammer's cranky father, Martin Crane, for 11 seasons on the hit sitcom.