When Peter Falk was bumbling around and annoying the prime suspect, he often made references to the missus. Was it just a ploy by Columbo (what was his first name, BTW), or was there a Mrs Columbo off screen?
Well, she never showed up in the original series (there was one episode where you thought you’d seen her picture but it was somebody else). However, she got her own series afterwards - played by Captain Janeway. In some other thread I read that this series apparently was so bad they changed the title so she no longer was Mrs. Columbo.
Oh and regarding the name, Snopes says no, but it might have been Frank.
Keeping it within the confines of the Columbo series, the answer seems to be yes. In one episode, taking place on a cruise ship, more than one crew member mentions seeing Mrs. Columbo at some point. In another, a nephew inquires to Columbo about his aunt.
So assuming these people weren’t hypnotized by Columbo or something, I think it’s safe to say that she existed. 
Oh, yeah, and once a killer tried to kill Mrs. Columbo. Plenty of acknowledgment in that one.
That’s the one I was thinking of, where you see all the pictures but it turns out to be somebody else.
I think he mentioned it was a picture of his sister.
Actually that’s the episode where you scratch your head and wonder if there really is a Mrs. Columbo at all, because he’s faked not only her picture, but her death, his own mourning and even her *funeral * just to entrap the villain. You wonder if he’s been faking her all along too.
Had to be a real person; who in real life eats lemon marmalade? You wouldn’t just make that up.
Amazing how I can remember that and I’ve never on purpose watched Columbo, it’s just always on when my parents watch it. Anybody catch the crazy one with Johnny Cash?!
Regarding the Mrs. Columbo show with Janeway, it was created by Fred Silverman and the Columbo creators Link & Levison absolutely hated it right from concept. They felt the mystery of his wife should be left alone. But since Silverman was going thru with it anyway they suggested a Jean Stapleton-type of actress.
They were appalled when he hired 26-year old, easy on the eyes, Kate Mulgrew (and made her the mother of his child as well!)
The show started out as Mrs. Columbo, then it was Kate Columbo, then finally Kate Loves A Mystery (then cancelled).