‘NCIS’: Mark Harmon Once Went Off-Script and Got Physical With Michael Weatherly

For over 400 episodes of NCIS, Mark Harmon appeared as Leroy Jethro Gibbs. Michael Weatherly appeared in 306 episodes of the series before departing in 2016. Harmon and Wetherly played off of each other for 13 seasons and so did their characters.

Gibbs’ signature head slap, often directed at Weatherly’s character Anthony DiNozzo, was never scripted. Harmon instinctively slapped Weatherly while filming season 1 to get him back on track, and it just stuck. 

What is the signature ‘Gibbs Slap’ on ‘NCIS’?

NCIS fans spent more than 18 seasons watching Mark Harmon bring his character, Leroy Jethro Gibbs, to life. Following his exit from the series, fans missed Harmon’s take on the character just as much as they missed his signature move, the “Gibbs Slap.” 

The “Gibbs slap” is the name given to Gibbs’ propensity to hit his colleagues on the back of the head. Weatherly’s character, DiNozzo, was the most common recipient of the slap, but other colleagues were treated to it occasionally, too. 

Mark Harmon’s ‘NCIS’ slap was completely off-script 

Gibbs might have been known for slapping his colleagues upside the head on a regular basis, but the writing team never intended for it to happen. The very first head slap was not written into the script. Harmon once explained that the slap was an instinctual move he used to try to get Weatherly back on track while they were filming. 

According to The Thing, Weatherly had gone off script during the early filming of the series, and Harmon reached over and swatted him on the back of the head. Instead of Weatherly breaking character, he rolled with the moment. The scene made it into the show’s fifth episode, and fans loved the action. It was soon inserted into episodes regularly until Harmon and Weatherly departed the show.

Why did Mark Harmon and Michael Weatherly leave ‘NCIS’? 

Michael Weatherly and Mark Harmon have both departed the NCIS cast. While they walked away from the series seasons apart, they ultimately gave up their characters for the same reason. Following the end of season 13, Weatherly opted to leave the series. At the time, he said he was walking away from DiNozzo to pursue other projects. 

Harmon left the series in 2021 after a bit more than 18 seasons as Gibbs. Harmon revealed that he decided to leave NCIS for the same reason as Weatherly. Harmon left the show to try on new characters and pursue new projects. He also was looking for a better life-work balance, as filming often took him away from his family. That doesn’t mean he would be against return, though.