Pat Mastelotto (born Lee Patrick Mastelotto) is a rock drummer who has worked with Mr. Mister, King Crimson and XTC, among others. For King Crimson he initially formed part of the "double trio", joining Bill Bruford on drums.

Mastelotto started playing the drums at the age of 10. When he was 16, he was playing in the most popular local bands and, while still in high school, commuted several hours to Lake Tahoe for gigs. Pat moved to Los Angeles in the mid-1970s and was discovered by Mike Chapman. He worked for many bands and as a studio session drummer, most notably with Scandal. Then in the mid-80s Pat was a founding member of Mr. Mister, a band that had two #1 hits. He did more session work with Al Jarreau, Pointer Sisters, Patti LaBelle, Kenny Loggins, Jude Cole, Eddie Money, Tina Arena, Martika, Jack Wagner, Danny Wilde, Mark Jordan, Matthew Sweet, Julia Fordham, Robyn Hitchcock, and bands like XTC, The Sugarcubes, Hall & Oates, Cock Robin, The Rembrandts, and The Sugarplastic. In 1991, Mastelotto co-produced Peter Kingsbery's first solo album. In 1993 he did a world tour with David Sylvian and Robert Fripp, with Trey Gunn and Michael Brook.

Since 1994 Mastelotto has been a member of King Crimson, and appears on over 20 King Crimson CDs and several KC videos. He also produced, edited and mixed several King Crimson ProjeKcts releases. He has also continued guesting on other projects (including Terrien's solo debut album *All the Dolls in the Same Place*, two more Cock Robin albums (2006, 2010), work with the Swedish I/B/ band, a duet with drummer Terry Bozzio, CGT, Mecca, and PJ Olsson).

His playing style is flexible, with a long history of mixing traditional acoustic drums with various banks of electronic gear. He is equally comfortable with simple pop grooves as he is with the ornate, dense arrangements of playing in bands like King Crimson.