His resulting four-day, clandestine trip to Havana over President’s Day weekend is documented on Wednesday’s episode of “Conan” (11 p.m. on TBS) — which finds the 6-ft., 4-in. red-haired host in a country where the locals don’t recognize him (and he has only an eighth-grade knowledge of Spanish with which to communicate).

“I felt really strongly about this — I don’t want this to be a snarky American comedy take. I don’t want this to be political,” O’Brien told a group of reporters over lunch in New York last week. “A lot of my [on-location sketches] are me as a fish-out-of-water … I want to go as a comedian who’s making fun of himself and I want to try and make the Cuban people laugh. In that regard I think we were successful.”

Plans for the Cuba trip were made quickly and under the radar — O’Brien didn’t even tip off his bosses at Time Warner. Instead, executive producer Jeff Ross contacted a production company in Havana who got a staff of 10 an invitation from the Cuban government to visit as part of a cultural exchange.

In the hour-long special, O’Brien learns to salsa dance, tries to play authentic Cuban music, gets a lesson in Spanish slang, goes to a rum factory, eats at a restaurant inside a family’s home and tries (unsuccessfully) to roll a cigar.

“Everywhere we went people were really open to meeting us,” he says. “The one thing that was a constant was [that] they’re very interested in how Americans feel about [them]. They’re relieved to hear the majority want to normalize relations. They want things to change, very much so.”

To replicate his talk-show set in Havana, O’Brien placed an old microphone on a cafe table, asked a group of female musicians to be his house band and found a guy to be “Cuban Andy Richter,” of whom he jokes “I actually have better chemistry with than the real Andy.”

After more than two decades as a late-night host — and greater competition in the genre than ever — the Harvard-educated O’Brien says mixing up the comedy-as-diplomacy reenergizes him.

“I’ve … been aggressively pursuing ‘what’s funny here’ [for 22 years] and this was a different agenda,” he says. “When we gave marching orders for the B-roll, it was just, ‘Get as much of this beautiful city as you can because it’s going to change, and it’s probably going to change quickly.’”