10 'NCIS' Guest Stars You Probably Forgot About

Jessica Napoli

After 15 seasons on television, you can say NCIS has weathered some intense storms — cast shakeups, character deaths, Mark Harmon's haircut.

The show continues to be a powerhouse for CBS, raking in high audience numbers each week, so it's no surprise the procedural drama was just renewed for Season 16 in April.

Pauley Perrette Mourns Death of a 'NCIS' Family Member

Pauley Perrette Mourns Death of a 'NCIS' Family Member

They worked together for 16 years.

With that longevity comes quite the number guest stars, with roles ranging from big to small. And since the series has been on for two decades, eagle-eyed fans can see much younger versions of some of the biggest stars on TV today.

Click through the gallery above to find out which big-time actors once starred on NCIS.

NCIS, Season 16, Fall 2018, CBS