The Grimes County Sheriff's Office said the 87-year-old was found by a housekeeper in his home in Todd Mission, Texas.
Investigators haven't disclosed how or when he died, but the sheriff's office said deputies are following up with Todd Mission authorities.
The Texas Renaissance shared the following statement:
"We are deeply saddened by the loss of George Coulam, founder of the Texas Renaissance Festival. For more than 50 years, he built a community that has become a cherished tradition for generations of performers, staff, and guests. At this time, we ask for respect and privacy for Mr. Coulam's family and the extended Texas Renaissance Festival family as they grieve. As this is a deeply personal matter, we are not offering additional comments at this time."
His sudden death comes weeks after he lost a lawsuit ordering him to sell the land and the festival.
The case stems from business dealings depicted in the HBO docuseries Ren Faire.
Over the show's three episodes, Coulam is shown engaging in negotiations with a party referred to as "The Greeks," but the $60 million deal falls through.
Those parties, a group that includes RW Lands, Texas Stargate, and Royal Campgrounds, sued Coulam to compel him to honor the contract.
It is unclear where the lawsuit stands following his death.