Janeane Garofalo was married for 20 years and didn’t even know it?

Janeane Garofalo was married for 20 years and didn’t even know it, until she needed to get divorced Saturday, The Post reports.

She explained at a New York Comedy Festival reunion for “The Ben Stiller Show” that she married a writer on the series — Rob Cohen, who went on to produce “The Big Bang Theory” — in Las Vegas as a joke in the 1990s, and didn’t realize the nuptials had stuck.

“Rob and I got married, for real, which we had to have a notary dissolve not 30 minutes before we got here tonight,” Garofalo said. “We were married for 20 years until this evening.”

She added: “We got married drunk in Vegas . . . We dated for a year, and we got married at a drive-through chapel in a cab. [We thought] you have to go down to the courthouse and sign papers and stuff, so who knew? We were married, and apparently now that [Rob] is getting married for real, his lawyer dug up something.”

Go to The Post for the full report.