Personal life
Hammett has been married twice. His first marriage to Rebecca lasted two years and ended in 1990, during the writing of the Black Album. He resides in San Francisco with his wife Lani (from January 31, 1998 to 2020) and two sons, Angel and Enzo.

Hammett enjoys surfing, cooking, archaeology, piercings, cars, and collecting horror movies. He is also known to be a vegetarian.

Likes listening to music by UFO, Black Sabbath, Deep Purple, Led Zeppelin, Joe Satriani, Warren Haynes, Adrian Belew, Freddie King, Buddy Guy, Jimi Hendrix, Kiss, Santana.

Suffers from attention deficit disorder (not in the hyperactive form). Also suffers from OCD.

On October 1, 2012, Hammett's first book Too Much Horror Business (a collection of photos detailing a lifelong love of monster movies and horror subjects) was released.