Club regulars said the pig was friendly and approached them for affection.
Kayleigh Parkin, the club's manager, said she was in her residence above the business when staff called her to report the uninvited customer.
"I live on the premises so I was upstairs, and the bar staff phoned me and said 'I'm sorry to disturb you but there's a pig in the bar,'" Parkin told ITV News. "They got some crisps from behind the bar and lured him outside with some cheese and onion."
Parkin said the pig was contained at the club's fenced-in garden and she posted about the animal on Facebook.
She said the owner of the pig, which turned out to be named Roddy, got into contact within 15 minutes and brought their pet home.
"Everyone was laughing about it. It was a bit of entertainment for a Tuesday night," Parkin said.