Joining Fields on the team, voted on by conference media, are placekicker Jaden Oberkrom, quarterback Casey Pachall and cornerback Jason Verrett.
TCU's four selections tied for second in the conference.
Fields, who appears on watch lists for the Chuck Bednarik Award, Bronko Nagurski Trophy and Rotary Lombardi Award, was the 2012 Associated Press Big 12 Defensive Player of the Year.
A native of Arlington, Texas, Fields led the Big 12 with 18 1/2 tackles for loss while placing third with 10 sacks.
As a true freshman last season, Oberkrom was a semifinalist for the Lou Groza Award. He was perfect on 42 extra-point attempts while going 22-of-30 on field goals. He ranked first nationally among freshman kickers and second in TCU single-season history with 108 points.
Pachall, on the Maxwell Award and Davey O'Brien Award Watch List, is the nation's leader among active quarterbacks in career passing efficiency with a 163.1 rating. His 15-2 record (.882) as a starting quarterback places second in TCU history behind only Jeff Ballard (19-2, .905).
Verrett, a 2012 All-American, was named by CollegeFootballNews.com as the nation's top cornerback. He's on watch lists for the Chuck Bednarik Award, Bronko Nagurski Trophy, Jim Thorpe Award and Lott Trophy.
Verrett topped the Big 12 last season in interceptions (six) and passes defended (22). He was the only player nationally to rank in the top 10 in both categories, tying for second in passes defended and sixth in interceptions. He also blocked a West Virginia field-goal attempt in the first overtime that paved the way for TCU to win 39-38 in double overtime.