Mularkey was born in Ft. Lauderdale, Florida. He attended Northeast High School in Oakland Park, Florida, and played quarterback for the Northeast Hurricanes high school football team.
Mularkey attended the University of Florida in Gainesville, Florida, where he played tight end for coach Charley Pell's Florida Gators football team from 1980 to 1982.
In 1983, Mularkey was a ninth-round draft pick for the San Francisco 49ers, but was cut before appearing in game. He went on to play with the Minnesota Vikings until the conclusion of the 1988 season. In 1989, he signed with the Pittsburgh Steelers as a free agent for the final three years of his playing career. In his nine NFL seasons, Mularkey played in 114 regular season games, started forty-six of them, and caught 102 passes for 1,222 yards and nine touchdowns.
Mularkey was given his first coaching position as an offensive/defensive line coach at Concordia University in St. Paul Minnesota for the 1993–94 season. He worked under head coach Tom Cross. He held the offensive/defensive lineman coaching position for one season.
Mularkey started his NFL coaching career in 1994 with the Tampa Bay Buccaneers as a quality control coach for both the offense and defense. In 1995, he was promoted to tight ends coach and held the position for one season.
Mularkey was hired as the Pittsburgh Steelers' tight ends coach in 1996 and held the position until the conclusion of the 2000 season, when he replaced Kevin Gilbride as the team's offensive coordinator. He has a reputation for being an offense-oriented head coach with a penchant for trick plays. His skill for creating special packages to utilize multi-dimensional players such as Hines Ward and Antwaan Randle El earned him the nickname "Inspector Gadget".
In 2004, Mularkey left the Steelers and was hired by the Buffalo Bills to succeed Gregg Williams as the team's head coach. Mularkey started out his first campaign as Bills head coach with a record of 0–4. He rallied his team to a 9–7 record by the end of the season, however, sparked by a six-game winning streak during which the Bills scored more points than in any other similar stretch in franchise history. However, a loss to the Steelers in the final game of the season kept the Bills out of the playoffs. Overall, they were 7th in the league in total offense. This would be their last winning season until 2014.
His second season in Buffalo was far less successful. Dogged by a quarterback controversy between J. P. Losman and Kelly Holcomb and a series of defensive personnel problems, Mularkey led the team to a 5–11 finish and a sixth consecutive year out of the playoffs - the longest such active streak in the American Football Conference (AFC). Mularkey's offensive schemes continued to be touted by then-general manager Tom Donahoe, despite the lack of production, finishing 24th in total offense.
On January 12, 2006, Mularkey resigned as head coach of the Bills, citing a disagreement in the direction of the organization, who had recently hired new management, including ex-coach Marv Levy.
On January 22, 2006, Mularkey was hired to be the Miami Dolphins' offensive coordinator. As the offensive coordinator under Miami's head coach, Nick Saban, Mularkey had an unsuccessful season with injuries to his first-string quarterback, Daunte Culpepper, and starting running back, Ronnie Brown. The Dolphins only scored 16.3 points per game, ranking 29th in the NFL. Following the season, it was announced Saban had resigned as Dolphins head coach and he accepted the position of head coach of the Alabama Crimson Tide football team at the University of Alabama on January 3, 2007.
Upon the hiring of former San Diego Chargers offensive coordinator Cam Cameron as Dolphins head coach on January 19, 2007, it was announced that Mularkey would no longer serve as offensive coordinator but would remain with the team in another capacity. On March 15, 2007 it was officially announced that Cameron himself would call the offensive plays in 2007, leaving Mularkey to serve as tight ends coach.
On January 25, 2008, it was announced that he would become the next offensive coordinator for the Atlanta Falcons. In his first season at Atlanta,
Mularkey's offense rushed for 152.5 rushing yards per game, second most in the league. The Falcons also finished 10th in the NFL in scoring (up from 29th the previous year) with 24.4 points per game, and 6th in yards with 361.2 per game. Mularkey was named the Assistant Coach of the Year by Pro Football Writers of America following the 2008 season.
Following a 13-3 season in 2010, Mularkey was named the Offensive Coordinator of the Year by Sporting News. Mularkey interviewed with multiple NFL teams for their head coaching vacancies for 2011.
On January 11, 2012, Mularkey accepted the head coaching job for the Jacksonville Jaguars, making him the third full-time head coach in franchise history. His first win came in Week 3 of the 2012 season against the Indianapolis Colts.
On January 10, 2013, the Jaguars terminated Mularkey after only one season. He had led the team to a 2–14 record. Mularkey had two years remaining on a three-year contract. However, Jacksonville Jaguars general manager David Caldwell, who had been hired on January 8, 2013, decided that the Jaguars needed "an immediate and clean restart" after winning only seven games in the past two seasons.
On January 22, 2014, the Tennessee Titans announced they hired Mularkey as their tight ends coach and he was given the title of assistant head coach for the 2015 season.
On November 3, 2015, the Titans relieved Ken Whisenhunt of head coaching duties and announced that Mularkey would step in as interim head coach for the remainder of the 2015 season. The Titans announced on January 16, 2016, that they would retain Mularkey as their full-time head coach, a highly criticized move by their fans and the media, who qualified the hire as "uninspired" and "awful".
He was given full control over his staff, and on January 18, 2016, he hired former Falcons WR Coach Terry Robiskie as the Offensive Coordinator and promoted assistant DC Dick LeBeau to Defensive Coordinator. He stated that the Titans would run an "Exotic Smashmouth" offense in 2016, meaning that they would go run-heavy, like a 1970s offense.
After starting the season 1–3, the Titans beat the Browns and the Dolphins to improve to 3–3. Thanks to a last minute win vs. Detroit in Week 2, blowouts against the Packers and the Dolphins on October 9 and November 13 respectively and a game-winning FG to beat the Chiefs in Week 14, the team came within just one game of earning an AFC South division title and a trip to the playoffs, ending with a 9–7 record, the first winning season for Tennessee since 2011. The Titans also sent five players to the Pro Bowl, their highest number since 2008.
* – Interim head coach
NFL head coaches under whom Mike Mularkey has served:Sam Wyche: Tampa Bay Buccaneers (1994–1995)
Bill Cowher: Pittsburgh Steelers (1996–2003)
Nick Saban: Miami Dolphins (2006)
Cam Cameron: Miami Dolphins (2007)
Mike Smith: Atlanta Falcons (2008–2011)
Ken Whisenhunt: Tennessee Titans (2014–2015)
Mularkey is married to Elizabeth "Betsy" Conant Mularkey, who is also a University of Florida graduate. The Mularkeys have two sons, Patrick and Shane.