Assistant coach Iowa Bielema returned to Iowa in 1994 to begin his coaching career under Fry as a graduate assistant. In 1996, he was promoted to
linebackers coach, a role he would hold until 2001. In 1998, Fry retired and was replaced by former Iowa offensive line coach
Kirk Ferentz, who had briefly coached Bielema in offensive line sets during preparation for the
1988 Peach Bowl. Bielema, one of the leading recruiters on Fry's staff, continued on the road recruiting during the coaching search. Ferentz retained only Bielema and quarterbacks coach
Chuck Long from Fry's staff.
Kansas State After the 2001 season, Bielema became co-defensive coordinator for the
Kansas State Wildcats, coached by
Bill Snyder, who had coached at Iowa with Fry for a decade. Bielema and Bob Elliott replaced
Phil Bennett, who had left to become the head coach of the
SMU Mustangs. Bielema coached the K-State defense for two seasons, helping the
Wildcats win the
2003 Big XII Championship.
Wisconsin Bielema left Kansas State after the 2003 season to become the
Wisconsin defensive coordinator under head coach
Barry Alvarez, who had also coached at Iowa under Fry. Bielema served as defensive coordinator for two seasons. In July 2005, Alvarez announced he would retire after the
2005 season and become the Badger athletic director. Alvarez also announced he had chosen Bielema as his successor, and would take over in 2006. In his first season as head coach of the Badgers in 2006, Bielema's team ended the regular season 11–1 (7–1 in Big Ten Conference play). With a 14–0 victory over
San Diego State on September 16, 2006, Bielema became the third Wisconsin head coach to win the first three games of his career. Later, with a 24–3 win over
Purdue on October 21, Bielema tied the record for most wins by a first-year coach at Wisconsin with seven. The other two coaches to complete this feat were
Philip King in 1896 and
William Juneau in 1912. A 30–24 victory over the
Fighting Illini on October 28, Bielema became the first coach in Wisconsin history to win eight games in his first season. With the 35–3 defeat of the
University at Buffalo on November 18, 2006, Bielema became the first coach in school history to win 11 games in the regular season. After a 17–14 victory over the
Arkansas Razorbacks in the
Capital One Bowl on January 1, 2007, he became the third coach in
NCAA history to win 12 games in his rookie season, finishing 12–1. He was named Big Ten Coach of the Year. Bielema coached Wisconsin to victories in 17 of his first 18 games. That represents the third-best start to a head coaching career in Big Ten history since Michigan's
Fielding H. Yost, who went 55–0–1 from 1901 to 1905. He led Wisconsin to a 5–0 start in the 2007 season. He finished with a 9–4 record and #24 ranking in the final AP Poll. In the 2008 season, the Badgers regressed to a 7–6 record, despite a 3–0 start. Coming off of a disappointing 2008 campaign, Bielema helped lead the team to a 5–0 start to the 2009 season. The team finished #16 in the AP Poll with a 10–3 record, which was bookended by a 20–14 over the
Miami Hurricanes in the
Champs Sports Bowl. On October 16, 2010, Bielema's
Badgers defeated #1-ranked
Ohio State, 31–18, in
Madison. It was Wisconsin's first victory over a #1-ranked team since
1981 when the
Badgers upset
Michigan. The victory against the Buckeyes would be his only one as he was 1–5 against Ohio State. The 2010 season ended with a loss to the
TCU Horned Frogs in the
Rose Bowl, 21–19. The team finished with an 11–2 mark and a #7 ranking in the final AP Poll. Bielema was named a finalist for the 2010
Bear Bryant Award which is given to college football's Coach of the Year. The other finalists were
Chris Ault of Nevada,
Gene Chizik of Auburn,
Mark Dantonio of Michigan State,
Jim Harbaugh of Stanford,
Chip Kelly of Oregon,
Gary Patterson of TCU,
Bobby Petrino of Arkansas, and
Mike Sherman of Texas A&M. In the 2011 season, Bielema led the team to an 11–3 record and a #10 ranking in the final AP Poll. Bielema is the only coach in Wisconsin history to lose consecutive Rose Bowls. In the 2012 season, Bielema and the Badgers finished with 8–5 regular season record that culminated in a 70–31 victory over
Nebraska in the
Big Ten Championship Game.
Arkansas On December 4, 2012, it was announced that Bielema was leaving Wisconsin to become the head coach of the Arkansas Razorbacks. He left partly to coach in the
Southeastern Conference (SEC) and partly because he felt that his assistant coaches were not being paid enough. Bielema replaced
John L. Smith, who had coached Arkansas to a 4–8 record during the 2012 season after
Bobby Petrino had been fired eight months earlier. Bielema's first season at Arkansas resulted in an overall record of 3–9, including 0–8 in the SEC. Bielema inherited a roster depleted of talent and lacking in development under Coach Smith. Bielema's starting quarterback also suffered a throwing shoulder injury, which limited his ability the entire season. It was the Razorbacks' worst SEC record since entering the conference in 1992 and their first winless in-conference season since
1942, when they were a member of the
Southwest Conference. Bielema's second season saw significant improvement, as Arkansas finished 7–6. Bielema won his first two SEC games in dominating fashion in November, beating #17
LSU by a score of 17–0 and #8
Ole Miss by a score of 30–0 to achieve bowl eligibility. Though Arkansas lost its remaining conference game against
Missouri, the Razorbacks were still the first unranked team in college football history to shut out two consecutive ranked opponents. Bielema led Arkansas to a
Texas Bowl victory in the postseason, defeating
Texas handily, 31–7. In Bielema's third season, the team suffered the loss of returning 1,190-yard starting running back Jonathan Williams before the season. Breaking in a new offensive coordinator and adjusting to losing three NFL drafted defensive players up front, the Razorbacks got off to a slow start, losing to
Toledo and
Texas Tech in the non-conference and started 2–4. Bielema then caught fire in the second half of the season, going 5–1 over the final six games, losing the one game to
Mississippi State on a missed field goal. Bielema ended the year by defeating one of his former mentors,
Bill Snyder, in the
AutoZone Liberty Bowl, as Arkansas dispatched
Kansas State, 45–23, to finish the season with a record of 8–5. Bielema's fourth season was a topsy-turvy campaign that ended with two embarrassing defeats at the hands of
Missouri in the regular season finale and
Virginia Tech in the
2016 Belk Bowl. The former saw his team blow a 17-point halftime lead and the latter was a 24-point blown halftime lead, which was the largest for Arkansas since at least 1952. With those losses Bielema's Razorbacks would finish the year at 7–6, a step back record wise from the year before. The losses led to the replacement of Defensive Coordinator
Robb Smith with former Iowa State head coach
Paul Rhoads, and other staff changes pointing to a change to a 3–4 defensive scheme. Bielema was the highest paid state employee in Arkansas with a salary reported at $4,200,000. Bielema's fifth season saw the program continue to regress, finishing 4–8 overall and going 1–7 in the SEC. On November 24, 2017, Bielema was fired after five seasons as Arkansas's head coach following a 48–45 loss at home to the
Missouri Tigers. The Razorbacks twice led by 14, but lost both leads. After the game, Bielema told reporters that he had been told he was being fired while he was coming off the field. According to
Fox Sports' Bruce Feldman, school officials decided to announce the firing after the game so he could have a chance to address the team one last time before they headed home for Thanksgiving. The alternative would have been learning of the firing via social media or a group text message.
NFL assistant coach New England Patriots Prior to the
2018 NFL season, Bielema was hired by the
New England Patriots as a defensive consultant to head coach
Bill Belichick. Bielema was promoted ahead of the season to defensive line coach. He won his first Super Bowl title when the Patriots defeated the Los Angeles Rams in Super Bowl LIII.
New York Giants On January 21,
2020, the Giants hired Bielema as their outside linebackers coach and senior assistant under
Joe Judge.
Illinois On December 19, 2020, Bielema was announced as the next head coach at the
University of Illinois Urbana–Champaign, succeeding
Lovie Smith. The school said Bielema would receive a six-year contract that paid $4.2 million the first year, with annual raises, based on performance and fulfilling media and other promotional obligations for the program throughout the contract. The salary made him the ninth-highest paid head coach among the then fourteen members of the Big Ten Conference. Bielema won his first game with the Illini against the
Nebraska Cornhuskers then went on a four-game losing streak to
UTSA,
Virginia,
Maryland and
Purdue. The streak ended with a win against
Charlotte, but he lost the next week to
Wisconsin, his former team. Following an off week, Bielema and the Fighting Illini
upset 24.5-point favorite
Penn State in Happy Valley, then ranked #7 in the AP Poll. The most notable part of this outcome was its nine overtime periods, which broke the FBS record for the most overtime periods in a game. The Illini lost their next game to
Rutgers before upsetting
Minnesota, then ranked #20 in the College Football Playoff poll. Bielema did not travel with the team to
Iowa having contracting COVID-19, and the Illini lost to the Hawkeyes with wide receivers coach
George McDonald serving as acting head coach. After Bielema returned, he won his final game of the season at home
against Northwestern. This marked the Illini's first win against the rival Wildcats since 2014. Bielema finished his first season at Illinois with an overall record of 5–7, and a Big Ten record of 4–5, which placed the Illini fifth in the Big Ten West Division. Bielema's second season at Illinois began with a victory over
Wyoming, a disappointing loss at
Indiana, followed by six consecutive victories over
Virginia,
Chattanooga, at
Wisconsin,
Iowa,
Minnesota, and at
Nebraska, making the Illini record 7–1. Bielema and Illinois could not maintain their win streak, dropping their next three games to
Michigan State,
Purdue, and at
Michigan. The Illini won their eighth game of the 2022 season by beating in-state rival
Northwestern in Evanston to close out the regular season with a record of 8–4. Illinois accepted an invitation to the
2023 ReliaQuest Bowl in Tampa on January 2, against the
Mississippi State Bulldogs. Mississippi State, inspired by the untimely death of their head coach
Mike Leach, beat Illinois 19–10 in the bowl. This was Illinois' first bowl game since 2019 and their first winning season since 2011. In the 2023 season, Bielema and the Fighting Illini finished with a 5–7 record. In the
2024 season, the Bielema-led Illini opened the season 4–0, with wins again
Eastern Illinois,
Central Michigan, and upset victories over the No. 19
Kansas Jayhawks and No. 22
Nebraska Cornhuskers, being ranked No. 19 in the country. The Illini then traveled to
State College for an emergency
white out matchup against the No. 9
Penn State Nittany Lions and lost 21–7. Following the loss, the Illini won two straight games, including a victory over the No. 24
Michigan Wolverines in the
Memorial Stadium Rededication Game, celebrating 100 years since
Red Grange's legendary performance against the Michigan Wolverines. The Illini then dropped a game to No. 1
Oregon in a blowout victory for the Ducks, and lost at home to the
Minnesota Golden Gophers in a close game where quarterback
Luke Altmyer fumbled the ball on a potential game-tying drive. The Illini then won three straight games, including a win at
Rutgers, where wide receiver
Pat Bryant scored a 40-yard touchdown on a pass from
Luke Altmyer with 14 seconds left to seal the victory. The three game win streak to end the regular season was capped off by reclaiming the
Land of Lincoln Trophy against the
Northwestern Wildcats. Illinois accepted an invitation to the
2024 Citrus Bowl against the No. 15
South Carolina Gamecocks, where they emerged victorious riding a 2 touchdown performance from running back
Josh McCray. The Illini finished the season with a 10–3 record, their first 10 win season since
2001 and first bowl game win since
2011. In May 2025, Bielema and Illinois agreed to a new contract that would keep Bielema signed through the 2030 season with an annual salary starting at $7.7 million for the 2025 season. Illinois started the season #12 in the AP Poll. He led Illinois to a 8–4 regular season record, which involved a win over #21 USC. Illinois defeated Tennessee in the Music City Bowl 30–28 to finish 9–4. ==Personal life==