Smith grew up in Bloomfield Hills, Michigan and attended Andover High School and Lahser High School, graduating from Lahser in 1980. While he was still at school, he ran away from home for a period of time. When he returned, his mother sent him to a boarding school. He then worked a series of jobs while playing in several bands, including Tilt, Tyrant, Terence and E-Trian. One of them, Toby Redd, put out a record; and opened for Kansas.

Later in his twenties, he moved to California, where his brother Brad lived, and ended up in Los Angeles where he joined the Red Hot Chili Peppers. He joined the Chili Peppers in late 1988 after their former drummer, Jack Irons, quit due to the distress and chaos of former guitarist Hillel Slovak's death from a drug overdose. According to Anthony Kiedis' autobiography Scar Tissue and Flea's liner notes on the Mother's Milk reissue, after Smith's first audition for the band, Anthony Kiedis told him he was allowed to join the band if he would shave his head, to test Smith's devotion to the band, but mostly because of Kiedis' dislike of Smith's more conformative Rock & Roll hair style (which Kiedis' likened to a Guns N' Roses look – long hair and a bandana), as it didn't mesh with the band's punk/funk, and alternative image. Smith came back the next day with his hair still in a bandana, yet was allowed to stay as Kiedis found his obstinacy impressive, and according to Flea, they liked his funk-groove drumming style.

Although he is mainly known as the drummer for the Red Hot Chili Peppers, Smith's drumming is featured on over a hundred albums in addition to those recorded with Red Hot Chili Peppers. He has also toured the world extensively performing drum clinics, and recently did a series of clinics with one of his drumming heroes, Deep Purple's Ian Paice. In 1993, Smith released Red Hot Rhythm Method, an educational video for aspiring drummers.

In November 2007, Smith performed a series of drum clinics in the UK, with legendary drummer Steve White. The drum tour went to places including Northampton, Cardiff, Birmingham, Newcastle, Manchester, Keighley, Norwich & Poole, with a massive turnout at all the venues.

At one point, Smith was developing a side project called "Chickenfoot" with former Van Halen members Sammy Hagar and Michael Anthony. However, Hagar has recently claimed that he no longer has time to commit to the band, so it has thus been abandoned.

In late 2007, Chad Smith has formed a new group, named Chad Smith's Bombastic Meatbats, featuring Cosmosquad guitarist Jeff Kollman, bassist Kevin Chown, and keyboardist Ed Roth. The band's debut album, which is due out in early 2008, has already been recorded and is currently in the mixing stages.

In a March 2007 edition of Doell & Ford Magazine, Smith was voted the number one drummer alive through the magazine's writers poll.

Chad's parents are Curtis and Joan Smith. He has two older siblings, Bradley and Pamela. He was married in 1994 to Maria St. John and while together they had one child: Manon St. John (1997), but the couple divorced the following year. He then had two other children, Justin in 1997 and Ava in 2001. He was then married to Nancy Smack on 8 May 2004 in Hopetown, Abaco, Bahamas and together they have a son Cole Madison.

When not on stage or in the studio Smith enjoys scuba diving, baseball, basketball, and riding his Harleys (he owns a black Road King that he has personally done modifications on, and in a 2006 interview with Modern Drummer magazine, said that his 2003 100th Anniversary issue Soft Tail was his "main mode of transportation"). He is also often noted as looking very similar to Hollywood actor Will Ferrell. He lives in a 1929 Spanish house that Cary Grant and Randolph Scott lived in together from 1932 to 1936. Ex-Deep Purple bassist Glenn Hughes recorded an album in Chad's home studio in late 2005 – early 2006.

Chad can also play a small amount of guitar and on his 2007 drum clinic tour with fellow drummer Steve White, he did a short guitar sequence in one of the clinics in Keighley, including a cover of Pearl Jam's 'Last Kiss' as a birthday tribute to a special fan.

The kit presently used by Smith is a typical example of a rock drum setup. He currently endorses Pearl Drums and Sabian cymbals. He has made with Pearl his own signature snare drum. The Chad Smith Signature Snare is a 14x5” inch snare which has a Black Nickel Plated Shell. Chad has also designed 2 signature crash-cymbals with Sabian - the 18.5" Chad Smith Explosion Crash and the 20.5" Chad Smith Explosion Crash. Chad also endorses Vater drumsticks and bass drum beater. He has a popular pair of signature sticks. The Chad Smith Funkblaster sticks have a unique shape wood tip which makes them stand out from Vater's other signature sticks.

In 2005, Pearl and CeeLite created a drum kit incorporating CeeLite's lighting technology to illuminate Chad's Pearl Masters kit on stage. Chad's new Pearl kit is wrapped with CeeLite's flat, flexible Light Emitting Capacitor (LEC) panels which can be programmed to dim, fade and flash. The kit features 4 ply 5 mm 100% aged maple shells with chrome hardware. Chad first played this kit on NBC's Saturday Night Live on the 5/6/2006. Chad also used a number of different snare drums on the 2006-2007 tour including the Pearl Sensitone and Yamaha's Jimmy Chamberlain signature snare drum.