Nathan Michael Sudfeld (born October 7, 1993) is an American professional football quarterback. He played college football for the Indiana Hoosiers and was selected by the Washington Redskins in the sixth round in the 2016 NFL draft. Sudfeld also spent four seasons with the Philadelphia Eagles as a backup quarterback, seeing occasional playing time and was a part of their Super Bowl LII-winning team.

Sudfeld took over as the starting quarterback at Modesto Christian School in Modesto, California, as a junior in 2010, replacing the Fresno State-bound Isaiah Burse. During his time there, he threw for 3,300 yards, 33 touchdowns, and 16 interceptions, earning the Trans Valley League Outstanding Offensive Player award, second-team all-state and first-team all-district honors as a senior.

Sudfeld received offers from UCLA, Indiana, New Mexico State and Arizona. He initially committed to Arizona, but after a coaching and system change, Sudfeld signed with Indiana.

Sudfeld got experience with the Hoosiers as a true freshman, in relief duty of Cameron Coffman, after starter Tre Roberson suffered a broken leg. He earned Big Ten Conference co-Freshman of the Week honours after leading a fourth-quarter comeback against Ball State. In his sophomore year, he split time with Tre Roberson, earning his first start against Bowling Green. He finished the season with 2,523 yards, 21 touchdowns, 9 interceptions and a 142.0 pass efficiency rating.

In Sudfeld's junior year, after both Cameron Coffman and Tre Roberson transferred to Wyoming and Illinois State respectively, he completed 60.5 percent of his passes for 1,151 yards with 6 touchdowns and 3 interceptions as the undisputed starter, before injuring his left shoulder against Iowa, which required surgery, forcing him to miss the rest of the 2014 season. Despite this, he was an Academic All-Big Ten selection and was named to the Manning Award watchlist.

Ahead of the 2015 season, his senior year, Sudfeld attended the Manning Passing Academy at Nicholls State University. He passed for 3,573 yards with 27 touchdowns during his senior season.

Sudfeld was selected by the Washington Redskins in the sixth round as the 187th overall pick in the 2016 NFL draft. On May 9, 2016, he signed a four-year, $2.5 million contract with the Redskins. Sudfeld did not see any playing time his rookie year, as he was inactive for all 16 games as the team's third-string quarterback behind starter Kirk Cousins and primary backup Colt McCoy. On September 2, 2017, Sudfeld was waived by the Redskins.

On September 3, 2017, Sudfeld was signed to the practice squad of the Philadelphia Eagles. He was promoted to the active roster on November 1, 2017. With the NFC's number one seed already clinched, Sudfeld made his first appearance in an NFL regular season game. He saw significant playing time during the season finale, completing 19 of 23 passes for 134 yards as the Eagles lost to the Dallas Cowboys by a score of 6–0. His 83% completion percentage set a new NFL record for completion percentage for a quarterback making his NFL debut (minimum 20 attempts). The record was previously held by Sam Wyche, who completed 80 percent of his passes for the Cincinnati Bengals against the Houston Oilers in 1968. In the NFC Championship against the Minnesota Vikings, he appeared in his first playoff game late in the 4th to take a knee down since the Eagles already locked up the 38–7 victory. The Eagles advanced to Super Bowl LII, where they won a close game against the New England Patriots 41–33, giving the Eagles their first Super Bowl win. Sudfeld was active as the backup to Foles, but did not play a down during the game. On December 30, 2018, Sudfeld came into the game against his former team to replace an injured Nick Foles and threw his first career touchdown pass to Nelson Agholor.