Comedian David Koechner Vapes Marijuana on Stage in Maryland

Comedian David Koechner's standup comedy act is smoking these days as some fans in Maryland discovered when he tried to catch a cannabis high on stage ... courtesy of an audience member, no less!

David hit the stage Friday night at Magooby's Joke House in Timonium, Maryland, where he performed for about an hour to a packed crowd, which included at least one fan who was puffing on a weed pen ... something Dave noticed from the stage.

Thirty minutes into his show, he must've caught a whiff of the sinsemilla, and decided to apply the golden rule -- sharing is caring!

Check out this video obtained by TMZ ... Dave looked out into the sea of people and asked, "Who is smoking? Is that weed?"

The man responded, "Yes" .... and motioning with his hand, David replied, "Give here."

The dude walked up to the stage and handed the vape to Dave, who started bantering with his fans as they egged him on to take a few tokes.

Dave finally caved and took two huge drags, blowing out the smoke. Of course, we can't tell from the video it really was marijuana ... but everyone in the crowd seemed convinced.

Assuming it was, it's NBD in Maryland ... where recreational cannabis was legalized last year.

We're not so sure puffing indoors at a comedy club is kosher -- but there were no narcs in the crowd, as David's show continued ... and, we're told everyone had a damn good time.

He's currently on a national comedy tour called "Blue Skies And Dirty Lies" -- and he's probably best known for his role as sportscaster Champ Kind in the 'Anchorman' movies.

You might recall in 2022 ... David was busted for driving while under the influence of alcohol in Ohio, receiving a ticket for the offense. He was also arrested and charged with DUI and hit and run in California's Ventura County on New Year's Eve 2021.