Sparks was born on September 25, 1969 in Cincinnati, Ohio, but grew up in Peaks Mill, Kentucky.

Sparks had his screen debut on the television movie Frog, starring Shelley Duvall, Elliott Gould, and Scott Grimes in 1987. Over the following decades he would go on to appear in several types of TV roles, which included host of Talk Soup in 1999, and was one of the stars of Disney XD’s Lab Rats.

While still in high school, he became the host of the short-run Saturday game show Treasure Mall in 1988, just months shy of his 19th birthday. Upon graduation, Sparks moved to Los Angeles and ten years later he was hired to host Talk Soup in 1999.

Sparks became the United States’ youngest game show emcee in 1988 when he hosted the short-lived, syndicated game show, Treasure Mall.

Sparks had made appearances on various television programs from as early as 1994, when he played a long-haired skateboarder on the fourteenth episode of the first season of Lois & Clark: The New Adventures of Superman. In 1995, he appeared in the “Gentle Horse” episode of Dr. Quinn, Medicine Woman. From 2000 through 2006, he appeared in Martial Law, Frasier, One on One, CSI: Crime Scene Investigation, and Las Vegas.

His first breakout role in a mainstream movie was in the 2000 cult favorite Dude, Where’s My Car?, as Zoltan, the bubble-wrapped leader of a clan of nerds obsessed with outer space. In a 2009 interview with We Are Movie Geeks, he confirmed he created the iconic hand gesture in a “Z” formation. The “Z” hand gesture became the celebratory sign of choice among the members and fans of baseball’s Pittsburgh Pirates, of whom Sparks is a fan, starting in 2012. On July 25, 2012, he threw out the first pitch during a Pirates/Cubs series at PNC Park.

In 2004, he starred as Deputy Dale in the independently produced Lightning Bug, which was written and directed by Robert Hall, who was an original bandmate in Hal’s hard rock band Zero 1.

In 2006, Sparks competed for the charity Habitat for Humanity on the Fox celebrity competition Celebrity Duets. He performed with such musical legends as Smokey Robinson, Gladys Knight, Wynonna Judd, Dennis DeYoung, Dee Snider and Sebastian Bach. He made it to the finale along with Lucy Lawless and Alfonso Ribeiro, and came in third in the series.

In addition to acting, Sparks is also the lead singer and guitarist for a rock band, ZERO 1 (previously called The Hal Sparks Band). At the start, the band consisted of Hal himself, his friend Rob Hall on bass and Hal’s cousin Miles Loretta on drums. Their self-titled debut album was released in December 2006 and produced by King’s X’s frontman DUg Pinnick. The album is available through iTunes and on Sparks’ official website.

In 2007, Sparks became the voice of the lead character in the animated series for children, Tak & the Power of Juju for Nickelodeon, (Replacing Jason Marsden) which ran for twelve episodes between 2007 and 2008.

In 2007, Sparks was cast as the host for the WB reality series Survival of the Richest, where wealthy young adults were paired with those young adults with massive debts to complete challenges together and work as a team.

Also in 2007, Sparks joined Roseanne to judge Nick at Night’s search for America’s Funniest Mom.

In 2007, both Sparks and Loretta from Zero 1 participated on Doug’s solo project Strum Sum Up.

He would go on to independently produce his first standup comedy DVD Escape from Halcatraz in 2008.

Sparks was a contestant on the 2008 VH1 celeb-reality series Celebracadabra, where the celebrities vie to out-perform each other with magic they have learned from their experienced coaches. Other celebrity contestants competing included Ant, Lisa Ann Walter, Carnie Wilson, Christopher “Kid” Reid, Kimberly Wyatt, and C. Thomas Howell. Howell was the winner, with Sparks taking second place.

Sparks is a regular guest on such programs as CNN’s Your $$$$$, The Joy Behar Show and The View when he’s not hosting his own weekly progressive radio show. He’s also participated in the Progressive Voices Cruise in 2009 and 2010. In 2011 he joined Stephanie Miller and John Fugelsang for the successful Sexy Liberal Comedy Tour in various cities across the country. This tour topped more than a million dollars in ticket sales while raising money for local progressive causes.

He provided the voice of the computer named “Mr. Q” on the U.S television adaptation of 20Q, which aired on the Game Show Network (GSN) in 2009.

In 2009, Sparks recorded his first Showtime comedy special Charmageddon in front of a standing-room-only crowd at the OC Pavilion in Santa Ana, California. The special aired in 2010, and was released on DVD.

He continued this free “behind the scenes” U-stream show for his listeners and fans. In June 2010 he got his own radio program on WCPT (AM) as host of The Hal Sparks Radio Program (megaworldwide), which broadcasts between 11am and 1pm CST each Saturday.

While at Los Angeles International Airport in 2010, Sparks and an airline passenger used CPR on an unconscious, elderly man who had collapsed in the airport terminal.

In 2011, Sparks was cast as Donald Davenport, one of the lead characters of a new Disney pilot Lab Rats. Variety reported on July 12, 2011 that the series was ordered by Disney for a 2012 premiere.

In 2011, Sparks began touring the US with John Fugelsang and Stephanie Miller as part of the Sexy Liberal Comedy Tour.

In May 2011, Sparks announced he would become a father during a special Ustream show on Father’s Day. He debuted his son Camden Harrison Sparks at the 2011 AIDS Walk in Los Angeles.

In early 2012, the Lab Rats premiere received the highest ratings for original series for the network. It was announced in May 2012, that it had officially picked up for another season.

In 2012, Sparks and Fugelsang began the “Politics, Sex and Religion Tour.”

In 2012, the Pittsburgh Pirates began using the iconic “Zoltan” hand gesture from Dude, Where’s My Car? as a good luck symbol to turn around a 19-season losing streak. After a Twitter campaign to encourage the “real Zoltan” to appear at a game, Sparks flew to Pittsburgh on July 25, 2012, to throw out the honorary first pitch, and was on hand to see the Pirates win 3-2 over his hometown team, the Chicago Cubs. Despite picking up a cult following in Pittsburgh and helping the team contend in the playoff race well into September, the Pirates finished with a 79-83 record, extending their major North American professional sports record to 20 consecutive losing seasons.

Sparks is a Freemason, having been initiated on November 6, 2016, at Los Angeles Lodge No 42 F. & A. M.

In 2019, Sparks appeared in the premier episode of Famously Afraid on the Travel Channel, a series in which celebrities tell of their personal unusual encounters, to describe his experience with alien abduction.