Whitta began his career as a writer and games journalist for ACE magazine. When ACE closed down in 1992, he became deputy editor of The One for Amiga Games and was involved with founding the original PC Gamer magazine in the UK. He subsequently served as the editor of Total Football. A few years later, he moved to the United States to become editor-in-chief of the newer, US version, of PC Gamer.

Besides his involvement setting up PC Gamer, Whitta has a long history of involvement with print and online magazines of all kinds. ACE magazine was owned by UK publisher Future Publishing, and in early 2000 Whitta worked with Future to establish a film magazine, Total Movie magazine. Due to financial difficulties at the publisher, Total Movie was canceled after only four issues in early 2001.

Whitta is also the writer behind a popular short series of comic books based on the Death, Jr. character, together with cover artist Mike Mignola and illustrator Ted Naifeh. Having been extended to a second three-part series, the writing has received praise as “charming and cleverly subversive” and for its “quirky characters and slick humor”. Whitta spoke about his experience writing this comic with Silver Bullet Comics in May 2005.

Whitta resides in the San Francisco Bay Area, California. In 2009, he became a US citizen.

Whitta was a frequent commentator on the PC Gamer podcast and he co-hosted the Game Theory podcast with Colin Campbell, which has since stopped being produced. In September 2011, Whitta and Campbell, then News and Features Editor at IGN, started a new podcast in the same vein as Game Theory, called IGN’s Game Business Show. He also commentated on the Next Gen podcast until the podcast was canceled.

He was a weekly co-host of This is Only a Test (Tested) and an occasional guest on Behind the Screened Door (Screened), the Giant Bombcast (Giant Bomb) the Comic Vine Podcast, before Whiskey Media was sold in two deals to CBS Interactive and BermanBraun. In October 2011, Whitta helped raise over $50,000 for Child’s Play when he co-hosted a 24-hour-long, live-streamed edition of This is Only a Test with Tested creators Will Smith and Norman Chan. Whitta continues to chair the Octoberkast charity event every year, creating the “Space Rocks” game in 2013. Whitta has returned as a guest on Giant Bomb’s Giant Bombcast in recent years.

He wrote the script for the action thriller film Undying. His latest screenwriting work was the sci-fi film After Earth. He was hired to script the first Star Wars stand-alone film, Rogue One, directed by Gareth Edwards. On 9 January 2015, he was announced to have amicably parted ways with the film.

On 27 October 2016, Variety reported that Warner Bros., Village Roadshow and Team Downey had put together a writers’ room for the third of the Guy Ritchie Sherlock Holmes movies, with several top names, including Whitta, Nicole Perlman, Justin Malen, Geneve Dworet-Robertson and Kieran Fitzgerald.

In November 2017, Whitta became an official co-host for the video game podcast, Kinda Funny Games Daily after numerous guest appearances on the show and one on Kinda Funny’s flagship podcast The GameOverGreggy Show.

In April 2020, Whitta launched a late-night talk show in the form of an online live stream set in the video game Animal Crossing: New Horizons, called Animal Talking. The show has featured several celebrity guests, including Elijah Wood, Brie Larson, and Danny Trejo.

On 21 August 2020, Whitta announced Talk Guys, a talk show based in the game Fall Guys: Ultimate Knockout.