Mark Duffner

{{Short description|American football coach (born 1953)}}

{{Use mdy dates|date=January 2019}}

{{Infobox NFL biography

| name = Mark Duffner

| image =

| alt =

| caption =

| current_team =

| position = Senior defensive assistant

| birth_date = {{Birth date and age|1953|7|19|mf=y}}

| birth_place = Annandale, Virginia, U.S.

| death_date =

| death_place =

| high_school =

| college = William & Mary

| pastcoaching =

• Ohio State (1975–1976)
  Graduate assistant
• Cincinnati (1977–1980)
  Defensive coordinator
• Holy Cross (1981–1985)
  Defensive coordinator
• Holy Cross (1986–1991)
  Head coach
• Maryland (1992–1996)
  Head coach
• Cincinnati Bengals ({{nfly|1997}}–{{nfly|2000}})
  Linebackers coach
• Cincinnati Bengals ({{nfly|2001}}–{{nfly|2002}})
  Defensive coordinator/linebackers
• Green Bay Packers ({{nfly|2003}}–{{nfly|2005}})
  Linebackers coach
• Jacksonville Jaguars ({{nfly|2006}}–{{nfly|2013}})
  Linebackers coach
• Miami Dolphins ({{nfly|2014}}–{{nfly|2015}})
  Linebackers coach
• Tampa Bay Buccaneers ({{nfly|2016}}–{{nfly|2017}})
  Linebackers coach
• Tampa Bay Buccaneers ({{nfly|2018}})
  Defensive coordinator/linebackers
• Cincinnati Bengals ({{nfly|2019}}–{{nfly|2024}})
  Senior defensive assistant

| pfrcoach = DuffMa0

| overall_record = NCAA: {{Winning percentage|80|40|1|record=y}}

}}

Mark Duffner (born July 19, 1953) is an American football coach who is the senior defensive assistant for the Cincinnati Bengals of the National Football League (NFL). Duffner served as the head coach of the Maryland Terrapins football team from 1992 to 1996.

Duffner was born and raised in the Washington, D.C. suburb of Annandale, Virginia; he played tackle for legendary coach Bob Hardage at powerhouse Annandale High School and played collegiately at the College of William and Mary, recruited to the school by assistant coach Bobby Ross. His first coaching job was as a Graduate Assistant under iconic coach Woody Hayes at Ohio State University followed by a stint as Defensive Coordinator for the University of Cincinnati Bearcats; he moved to Holy Cross in the same role in 1981 and ascended to the Head Coach position in 1986, compiling a stellar 60–5–1 record.{{Cite news |title=DUFFNER, TRYING FOR EVERYTHING |url=https://www.washingtonpost.com/archive/sports/1992/04/29/duffner-trying-for-everything/6e9d6078-bf8e-4779-a1ef-10eee6cafbc2/ |access-date=2022-04-07 |newspaper=The Washington Post}} At Maryland, Duffner compiled a 20–35 record, his most important legacy at Maryland has been in the record books; most of the Terps' longstanding single game, season, and career passing and receiving record were broken during his tenure. This was due to the implementation of his run and shoot offense and quarterbacks John Kaleo, Scott Milanovich, and Brian Cummings. However, his teams were notoriously weak on defense, frequently giving up points so fast that even his prolific offense couldn't keep up. Duffner's only winning season came in 1995 when the Terps finished with a 6–5 record and started with four consecutive wins.

After leaving Maryland, Duffner became an assistant with the Cincinnati Bengals from 1997 to 2002, where he served as linebackers coach and then defensive coordinator. From 2003 to 2005, he served with the Green Bay Packers. In early 2006, he was signed by the Jacksonville Jaguars as the linebackers coach. He was hired by the Miami Dolphins in January to be their linebackers coach for the 2014 season. On October 15, 2018, Duffner was named as the new defensive coordinator of the Tampa Bay Buccaneers.{{cite web|url=https://www.buccaneers.com/news/mark-duffner-replaces-mike-smith-as-buccaneers-defensive-coordinator|title=Mark Duffner Replaces Mike Smith as Buccaneers' Defensive Coordinator|publisher=Buccaneers.com|access-date=October 15, 2018}}

Duffner was hired by the Bengals as a senior defensive assistant on March 7, 2019.{{cite news |author=Dehner, Paul Jr. |title=Cincinnati Bengals add veteran Mark Duffner to club's largest staff ever |url=https://www.cincinnati.com/story/sports/nfl/bengals/2019/03/07/cincinnati-bengals-add-veteran-mark-duffner-clubs-largest-staff-ever/3090899002/ |website=Cincinnati.com |publisher=The Cincinnati Enquirer |date=March 7, 2019 |access-date=November 29, 2020}} He missed the team's week 10 game in 2020 against the Pittsburgh Steelers due to COVID-19 pandemic protocols.{{cite news |author=Hobson, Geoff |title=Three Bengals Defensive Coaches Ruled Out For Covid-Related Issues |url=https://www.bengals.com/news/three-bengals-defensive-coaches-ruled-out-for-covid-related-issues |website=Bengals.com |date=November 15, 2020 |access-date=November 29, 2020}}

Duffner was fired by the Bengals at the end of the 2024 season.{{Cite web |last=Roling | first=Chris |date=January 12, 2025 |title=Zac Taylor's Bengals make more changes to coaching staff |url=https://bengalswire.usatoday.com/2025/01/12/zac-taylor-bengals-more-changes-coaching-staff/ |access-date=January 13, 2025 |website=Bengals Wire | publisher=USA Today |language=en}}

The surname Duffner originates from the German habitational name for someone from Teufen in Württemberg or from Tüffen near Saint Gallen, in Switzerland.{{cite book |title=Dictionary of American Family Names |edition= 2 |publisher=Oxford University Press |year= 2022}}