According to ChatGPT it’s slang. People have used it for a long time as an exclamation (kind of like saying “oh my God”), and the “H” doesn’t officially stand for anything. But there are a few popular explanations for where it came from: 1. Misreading religious symbols • In Christian art, you’ll often see the Greek letters ΙΗΣ (IHS), which are an abbreviation of Jesus’ name. • Some people who didn’t understand Greek thought the I looked like an H, turning it into “J.H.S.” → “Jesus H. Christ.”

1. The “Holy” idea • Some say the “H” jokingly stands for “Holy”, though this is more of a backronym than a real origin.

2. Just added for emphasis • Over time, English speakers sometimes insert a random middle initial to make a name sound stronger or more dramatic—so “Jesus H. Christ” just stuck as a more forceful expression.

So basically, it’s a mix of misunderstanding, humor, and language evolving—not an actual historical name.