Mark Harmon’s Iconic Slap to Michael Weatherly Was Unscripted — The Shocking Truth!

One of NCIS‘s most iconic and enduring moments was born spontaneously during the first season. In episode five, titled “The Curse,” Mark Harmon, as Special Agent Leroy Jethro Gibbs, slapped Michael Weatherly’s character, Special Agent Anthony “Tony” DiNozzo, on the back of his head. This unscripted action, which came to be known as the “Gibbs slap,” quickly became a signature move in Gibbs’ interactions with Tony.

In an interview with French publication Premiere (via Showbiz CheatSheet), Mark Harmon explained how the moment unfolded:
“We were filming a scene, and Michael was on a Navy ship talking to a female petty officer. It was early in season one, and he was doing his thing—sometimes staying on script, sometimes not. I just reached over and smacked him. It wasn’t planned; it was instinct. I didn’t think about it, I just did it.”

Harmon praised Michael Weatherly for staying in character despite the surprise slap:
“To his credit, he stayed in the scene and didn’t break. I didn’t break either. The actress playing the petty officer was shocked, but she stayed in character, and we just kept going. People liked it. After that, I started doing it more often—maybe too much. Now, we use it sparingly, but that’s how it all started.”

The Dynamic Behind the Scenes
Mark and Michael’s relationship off-screen mirrored the contrasting personalities of their on-screen counterparts. They worked together for 13 years, from 2003 to 2016, until Michael’s departure. However, their dynamic was not always harmonious in the beginning.

In a 2007 interview with Futon Critic, Michael described their early relationship as being on opposite ends of the spectrum:
“Mark Harmon and I were on different poles. I was Antarctica; he was the North Pole. We’d just look at each other like, ‘What’s going on with your polarity?’”

Michael recalled one moment from the early days of filming to highlight their differences:
“When CNN Showbiz Today asked me about the best part of doing the pilot, I said, ‘I got a rubber gun and a fake badge.’ Mark looked at me like, ‘That’s your answer?’”

A Shift in Perspective
Years later, after starring in Bull from 2016 to 2022, Michael Weatherly gained a newfound appreciation for Mark’s leadership. Reflecting on his experiences, he shared in an interview with USA Today (via Looper):
“Being the lead of Bull gave me great insight and respect for what Mark Harmon was doing all those years. When I used to think, ‘Why doesn’t he have as much fun as the rest of us?’ it started to make sense.”

The “Gibbs slap” remains a fan-favorite moment, representing the unique bond between Gibbs and Tony. It stands as a testament to how authentic moments of improvisation can create lasting and memorable interactions, cementing their place in NCIS history.