Knoxvilled posted a photo from behind the bar on Instagram, showing a surprised crowd greeting him as they ordered drinks.
"Bartending the Barnstable Brown party in Louisville, Ky tonight," he wrote. "Kentucky Derby tomorrow, woohoo! #actionpointmovie."
Knoxville posted another photo on Saturday afternoon, standing beside a woman in a massive sunhat for the occasion.
"With the Hat of the Day at the Kentucky Derby," he wrote.
The 47-year-old star of Jackass has been promoting his upcoming movie, Action Point on every platform. The film appears to rely on a theme similar to Knoxville's previous work -- slapstick humor and practical stunts -- but it also has more of a story to it than Jackass.
In Action Point, Knoxville plays an aging man who tells his grandchild the story of his underdog amusement park. The trailer alone features innumerable slapstick gags, punctuated with Knoxville's trademark crass sense of humor.
Alongside Knoxville, the film stars Brigette Lundy-Paine and comedian Johnny Pemberton.
Action Point will be Knoxville's first film release since 2013's Bad Grandpa. That movie followed an 86-year-old man trying to take his 8-year-old grandson on a cross-country trip to meet his biological father. The movie made about $150 million at the box office -- about ten times its budget, but has a 60% rating on Rotten Tomatoes with both critics and audiences.
In a recent interview with PopCulture.com, Knoxville disclosed his most brutal injury from a long career as a stunt man. He said that he had once broken a bone in his face that then caused his eye to "pop out" of his head.
"That was pretty traumatizing," he said.
This year, Knoxville and the rest of the Jackass crew have had a lot to celebrate and a lot to mourn, as their co-star Steve-O celebrated his tenth year of sobriety, while Bam Margera suffered a backslide, ending in a DUI arrest.
"Hard to believe it's been an entire decade since I've had a drink or a drug," Steve-O wrote on Twitter in March. "I just can't put into words how grateful I am for [Johnny Knoxville] and the rest of the guys who locked me up in a psychiatric ward on March 9, 2008, where this journey began," he wrote. "Thank you, dudes, I love you."
Meanwhile, Margera pleaded not guilty to driving under the influence in February.