Jack Steven Irons (born July 18, 1962) is an American drummer and multi-instrumentalist. He is best known as the founding drummer of the American rock band Red Hot Chili Peppers, and as a former member of Pearl Jam, with whom he recorded two studio albums. He also played on the last song from Vitalogy, "Hey Foxymophandlemama, That's Me" (he had replaced Dave Abbruzzese at the end of the album's recording sessions).
Alongside his work with Red Hot Chili Peppers and Pearl Jam, Irons has been a member of Eleven, The Wallflowers and Mark Lanegan Band. He has worked with Joe Strummer and The Latino Rockabilly War, Redd Kross, Raging Slab, Spinnerette and The Les Claypool Frog Brigade. In 1995 Irons and the other members of Pearl Jam recorded and toured the Mirror Ball album with Neil Young. In 2004, Irons released his first solo album, Attention Dimension, and released his second, No Heads Are Better Than One, in 2010.
Irons was inducted into the Rock and Roll Hall of Fame as a member of the Red Hot Chili Peppers on April 14, 2012. Irons, along with former drummer Cliff Martinez, joined the band onstage for the first time in 24 years for a performance of their 1991 hit, "Give It Away". Irons was an opening act in 2017 for the Chili Peppers on The Getaway World Tour.