
William Michael "Billy" Zabka (born October 20, 1965) is an American actor, martial artist, screenwriter, and film producer. Zabka is best known for his role of Johnny Lawrence in The Karate Kid (1984), The Karate Kid Part II (1986), and decades later reprises the role of Johnny in the Netflix series Cobra Kai (2018-), along with Ralph Macchio as Daniel.
During the 1980s, Zabka appeared in the comedy movies Just One of the Guys (1985) and Back to School (1986). Zabka also co-starred on the CBS television series The Equalizer as the son of the title character (1986–89). He also played Jack, Audrey's jock boyfriend, in National Lampoon's European Vacation (1985).
During the 1990s and 2000s, he acted mostly in independent films while studying to be a filmmaker. In 2003, he wrote and produced the short film Most, shot on location in the Czech Republic and Poland. Most (aka The Bridge) had its world premiere at the Sundance Film Festival 2003 and won numerous awards at prestigious film festivals, including Best of Festival at the Palm Springs International Festival of Short Films in 2003. In 2004, he was nominated for an Academy Award for Most in the Live Action Short Film category.

Karate Kid: Legends
2025 · as Johnny Lawrence

The Karate Kid
1984 · as Johnny Lawrence

Hot Tub Time Machine
2010 · as Rick

The Karate Kid Part II
1986 · as Johnny Lawrence

National Lampoon's European Vacation
1985 · as Jack

Smiley Face
2007 · as Prison Guard

Where Hope Grows
2014 · as Milton Malcolm

Just One of the Guys
1985 · as Greg

Back to School
1986 · as Chas

Wild Roomies
2004 · as Slick Salesman

High Voltage
1997 · as Bulldog

Python
2000 · as Greg Larsen

Landspeed
2002 · as Bob Bailey

Epoch
2001 · as Rover Driver Joe

The Cobra Kai Movie
2024 · as William Zabka

Jake Paul vs. Mike Tyson
2024 · as Self

Shootfighter: Fight to the Death
1993 · as Ruben

Shootfighter II
1996 · as Ruben