Merritt was born in Greenville, Illinois, to a food scientist father who worked on the Coffee-Mate project. Merritt received a BS in journalism from the University of Illinois at Urbana-Champaign and pursued graduate work in communications at the University of Texas at Austin.
Merritt's career in radio began in 1986 as a DJ for WGEL, a country music station located in Greenville, Illinois. In 1993, he worked as an intern for National Public Radio's "Morning Edition". From 1999 to 2004 Merritt worked for TechTV in San Francisco as an Executive Web Producer and served as a radio host with TechTV until 2003.
Merritt started with CNET in 2004. In addition to his duties as co-host of Buzz Out Loud with Molly Wood, Merritt also had a regular column & podcast (co-hosted with Rafe Needleman) dealing with consumer technology. He also co-hosted the tech support call-in program CNET Live with fellow editor Brian Cooley, and was the host of CNET Top 5.
On April 16, 2010, Merritt announced he would be stepping down as co-host of Buzz Out Loud, and that he would be joining the TWiT.tv Network as a full-time daily host beginning June 1, 2010. During his last Buzz Out Loud episode on May 14, 2010 he announced that his main focus at TWiT.tv would be a new daily show, Tech News Today.
Prior to joining TWiT as an employee, Merritt had a long-standing working relationship with former TechTV colleague Leo Laporte's network having regularly appeared on This Week in Tech as either a guest or as a relief host. His general discussion podcast with Roger Chang, East Meets West, also featured on TWiT Live.
Tech News Today launched on 1 June 2010. Merritt was a regular host along with Sarah Lane, Iyaz Akhtar and Jason Howell.
Upon joining TWiT.tv, Merritt brought with him two shows previously produced by cartoonist Scott Johnson's Frogpants Studios. Originally started on July 7, 2009, "Fourcast" featured Merritt and Johnson inviting various guests to discuss the future and what it might contain in a so-called virtual fireside setting. Meanwhile, "Current Geek Weekly" is a weekly discussion of geek culture stories and the companion podcast to the Current Geek podcasts still produced by Frogpants Studios. Merritt still appeared on the Frogpants Network for a segment called "Tom's Tech Time" on Wednesdays on the Scott Johnson/Brian Ibbott-hosted podcast The Morning Stream.
On 10 November 2010, Merritt officially launched his second new show on TWiT, FrameRate. Focusing on video in its many and varied forms (TV, Film, Internet), Merritt co-hosted the show with magician and NSFW podcast host Brian Brushwood.
On 20 January 2011, TWiT officially launched "Triangulation", a new show Merritt co-hosting with Leo Laporte and interviewing a notable figure in technology. In July 2012 he stopped hosting the show because he "wanted to work on other projects".
In addition to these regular shows, Merritt hosted live breaking news coverage of major technology events on TWiT Live such as WWDC, Google I/O and the resignation & passing of Steve Jobs. These are later released as "TWiT Live Specials" podcasts. He has acted as a relief host for Laporte on TWiT, Windows Weekly, Security Now and other shows when Laporte has been unavailable.
On 22 October 2012, Merritt announced that he would be moving to Los Angeles to accommodate his wife's new employment at YouTube, but would still continue to present on the TWiT network over Skype.
On 5 December 2013, Leo Laporte announced that Merritt's contract would not be renewed. Leo stated that the decision was based on the need for an in-studio anchor for Tech News Today. Merritt hosted his last edition of Tech News Today on 30 December 2013.
Since 4 February 2008, Merritt has hosted Sword & Laser, a sci-fi based book club podcast, co-hosted with his former CNET colleague, Veronica Belmont.
On June 22, 2010, he launched a new show for Revision3, entitled Tom's Top 5. The show counts down a new Top 5 list every week, and is released every Tuesday. Its final episode was published on November 1, 2011. He did a similar show on CNET.
Merritt has written a sci-fi novel, Boiling Point, which describes a near future United States civil war. He later narrated it as an audiobook.
In 2006 he wrote another novel, United Moon Colonies, of which he posted chapters on his blog. Both novels were published on Lulu.com with a Creative Commons license.
Merritt appeared in 2 early episodes of his Frame Rate co-host Brian Brushwood's Revision3 show Scam School.
On March 3, 2013, Merritt and Molly Wood began the It's a Thing podcast. According to the site's about page, "It’s a Thing is a show grown from the brain of Molly Wood, derived from a regular segment on the CNET podcast Gadgettes. Tom and Molly started the hit podcast “Buzz Out Loud” which they co-hosted for years after the turn of the century. They missed doing shows together, so they decided that in itself, should become a thing. Again."
In early January 2014 Merritt began co-hosting a podcast with Brian Brushwood called Cordkillers, while also starting a beta for a new Daily Tech News Show.
In 2012, newspapers reported calls by consumer groups to boycott Apple products in response to accounts of worker suicides and dangerous working conditions at the Foxconn plant in China. Merritt, who has followed tech news since 2005, responded by saying "Boycotts of Apple might be good to nudge Apple into doing something to improve conditions, but, you're going to have to boycott buying electronics if you really wanted to punish China. I'm not sure that that's called for, necessarily."
Citing a Forbes infographic showing Foxconn with, reportedly, fewer suicides per million workers (18) than the number of suicides per million Chinese citizens (220), Merritt suggested it might be worth investigating whether the lower rate at Foxconn may be due to “the fact that people who are gainfully employed are in some way less likely to commit suicide." There may be other reasons besides the working conditions at the plant for worker suicides.
Instead of boycotts, he advocated addressing the dangerous working conditions in a broader context. Comparing the conditions at Foxconn to coal mines of the 1800s and early 1900s, he added, "There may be similar types of abuses going on at Foxconn, but we have those kinds of conditions arise because the conditions that the workers are in before they take the job are worse. That doesn't excuse the conditions, but you don't just want to get rid of the factory. You don't want to just get rid of the coal mine and send people back into abject poverty. What you want to do is put pressure on the coal mine or the factory or whatever to begin to change their ways and improve those conditions so that everybody wins."
Merritt is married to Eileen Rivera and they live in Los Angeles, California, with their dog Sawyer (another dog, Jango, died of natural causes on January 25, 2017), and formerly lived in Marin County and Oakland. Merritt is a fan of Major League Baseball's St. Louis Cardinals.