Defensive end (DE) is the name of a defensive position in the sport of American and Canadian football.

This position has designated the players at each end of the defensive line, but changes in formations have substantially changed how the position is played over the years. Eleven-time pro bowler and National Football League Hall of Famer Bruce Smith of the Buffalo Bills, usually considered one of the best defensive ends ever, is the all-time leader in career sacks with 200.

Early formations, with six- and seven-man lines, used the end as a containment player, whose job was first to prevent an "end run" around his position, then secondarily to force plays inside.

When most teams adopted a five-man line, two different styles of end play developed: "crashing" ends, who rushed into the backfield to disrupt plays, and "stand-up" or "waiting" ends, who played the more traditional containment style. Some teams would use both styles of end play, depending on game situations.

Traditionally, defensive ends are in a three-point stance, with their free hand cocked back ready to "punch" the offensive lineman, or in a "two-point stance" like a linebacker so they can keep containment. Some defensive ends play the position due to their size; they close down their gap so the running back has no hole to run through. Other ends play the position due to their speed and agility; they are used to rush the quarterback. These ends can time the snap of the ball in order to get a jump on the rush.

Julius Williams (born July 19, 1986 in Decatur, Georgiais a Canadian football defensive linemen who is currently playing for the Edmonton Eskimos. He was signed by the Jacksonville Jaguars as an undrafted free agent in 2009. He played college football at Connecticut.

Williams has also been a member of the Hartford Colonials.

Williams signed with the Jacksonville Jaguars in the spring of 2009 and was one of only two undrafted free agents to make the opening day roster. As a rookie, he was active for 11 games and started one contest at defensive end. He was released by Jacksonville at the final cut down in 2010 and joined Hartford of the UFL for the final weeks of that league's inaugural season.

Williams signed with the Edmonton Eskimos on April 1, 2011. He began the season on the 1-game injured list with a dislocated elbow. He was activated for Game 4 and in 15 games (15 starts) had 20 defensive tackles, 5 quarterback sacks and a tackle for a loss. Julius also started the Western Semi-Final (1 defensive tackle and a quarterback sack) and the Western Final (1 defensive tackle).

Jadeveon Clowney (born February 14, 1993) is an American football defensive end. He recently graduated from South Pointe High School in Rock Hill, South Carolina. Clowney was named South Carolina's 2010 Mr. Football, and considered the consensus No. 1 football recruit in the United States for his class.

For the 2010 season, Clowney had 162 tackles, 29.5 sacks, 29 tackles for loss, 11 forced fumbles, 6 fumbles recoveries, 43 quarterback pressures and five defensive touchdowns. South Pointe was 38-6 during his three varsity seasons. He is considered the best college football prospect in recent memory.

Clowney was named by ESPN, as well as Scouts and Rivals, as the top college football recruiting prospect in the nation leading into the 2011 NCAA Signing Day, (February 2, 2011). Clowney himself stated in an interview that he had narrowed down his prospects to the Alabama Crimson Tide, the Clemson Tigers, and the South Carolina Gamecocks; however, he did not commit on National Signing Day. On February 14, 2011, his 18th birthday, Clowney committed to the University of South Carolina.

Dwight Jason Freeney (born February 19, 1980) is an American football linebacker for the Indianapolis Colts of the National Football League (NFL). He played college football for Syracuse University, and earned All-American honors. He was drafted in the first round of the 2002 NFL Draft, has played his entire pro career for the Colts, and is a seven-time Pro Bowl selection.

Freeney attended Bloomfield High School in Bloomfield, Connecticut. Freeney was a four-sport letterman, earning four letters in baseball in which he was coached by Alphonso Ford; four in basketball; three in football, in which he played both ways; and one in soccer, in which he played goalie in his freshman year before switching over to football. Freeney currently holds the record for sacks at his high school and most sacks in a high school career in the Connecticut record book. Bloomfield High retired his No. 44 football jersey. During his youth, Freeney idolized New York Giants linebacker Lawrence Taylor, whom he met at a charity golf tournament after turning pro.

Derrick Vincent Thomas (January 1, 1967 – February 8, 2000), nicknamed D.T., was an American football linebacker and defensive end for the Kansas City Chiefs of the National Football League (NFL). He played his entire 11-year career for the Chiefs after being drafted fourth overall in the 1989 NFL Draft. Thomas, part of the class of 2009 entering the Pro Football Hall of Fame, was a premier football player throughout the 1990s and is considered one of the best pass rushers of all-time. In 1990 against the Seattle Seahawks, he set an NFL record with seven sacks in a single game. On February 8, 2000, Thomas died from a massive blood clot that developed in his paralyzed lower extremities and traveled to his lungs. His paralysis was the result of severe injuries sustained in a car accident weeks earlier.

Born in Miami, Florida, Thomas was raised by his mother. His father, Air Force Captain and B-52 pilot Robert James Thomas, died during a mission in the Vietnam War. Thomas started playing football when he was three years old. He played high school football at South Miami Senior High School.