This will probably sound like a really stupid question, but it’s coming from someone who doesn’t watch TV or movies, so I’m just not up on pop culture stuff.
I can figure out what “my bad” means from context, but I’m curious – where did it originate? From a catchphrase of a TV sitcom character? In a movie? Would someone be kind enough to enlighten the clueless one? Thank you!
Basketball courts of the 1980’s. Perhaps slightly earlier, but not much.
Ah. So it’s been around that long? Interesting; I don’t recall hearing it until the last few years. Which may say more about me = clueless than the phrase’s popularity. 
I know that sports slang (like the jargon of many other specialties) can take a while to filter out to the general populace after it’s established within its own niche. Has any particular celebrity used the phrase fairly recently and popularize it?
Thanks for the answer!
I thought it sprang up around 1991 or so, and was made popular by Pauli Shore (the “Weasel”). I don’t know, but that’s when I first heard it getting pouplar.
I meant to imply that the term was in use, probably on street courts in the US, by the late 1980’s. As for how it reached the rest of the US and when, I don’t know.
As best as I can trace it back, it comes from the sports world. Often something said to teammates on a bad serve, such as in volleyball, etc. It then was picked up in urban slang and TV followed cultural practices.
And oh, it does go back a ways in England too. They were very polite on the court the further back you go.
I’m English and I’d never heard the phrase until moving to the US 7 years ago.
I am not sure who coined the term. It was either Bubba or Rollo.
We said it in middle school (ca. 1975).
Impressive MBS…
OED:
“1986 C. WIELGUS & A. WOLFF Back-in-your-face Guide to Pick-up Basketball 226 My bad, an expression of contrition uttered after making a bad pass or missing an opponent.”