Ralph George Macchio Jr. was born in Huntington, New York in 1961. He is the son of Rosalie DeSantis and Ralph Macchio, Sr., both of Italian ancestry.
Macchio began tap dancing lessons at the age of 3 and was discovered when he was 16. He was then cast as Jeremy Andretti in the television series Eight Is Enough. After Eight is Enough ended, he won the role of Johnny Cade in the 1983 film The Outsiders. It was this role that led him to be cast as Daniel LaRusso in the 1984 film, Karate Kid and two of its sequels, The Karate Kid Part II and The Karate Kid Part III. Macchio appeared in the 1986 film Crossroads, portraying music student Eugene Martone. Also in 1986, Macchio starred in Cuba and His Teddy Bear on Broadway, alongside Robert DeNiro. In 1992, he starred opposite Joe Pesci and Marisa Tomei in the hit comedy My Cousin Vinny, playing Billy Gambini, who was wrongfully accused of murder while passing through a small Alabama town. In 1996, Macchio performed the lead role of J. Pierrepont Finch in the U.S. tour revival of the 1962 Tony Award-winning musical How to Succeed in Business Without Really Trying, and received positive reviews.
As of November 2008, Macchio was ranked No. 80 among VH1’s 100 Greatest Teen Stars. Macchio is currently reprising his role as Daniel LaRusso in Cobra Kai, an action comedy-drama YouTube Premium series presented in an episodic storytelling format, that began in 2018. He is also a co-executive producer of the series, along with William Zabka. The series is set 34 years after the events of the 1984 All Valley Karate Tournament and revolves around a down-and-out Johnny Lawrence (Zabka) who – seeking to get his life back on track, and obtain redemption for his defeat in the 1984 tournament – reopens the Cobra Kai dojo. This reignites his rivalry with a now-successful LaRusso, who has been struggling to maintain balance in his life without the guidance of his now-deceased mentor, Mr. Miyagi.