Billy Lange

William Lange
Born	(1972-02-11) February 11, 1972 Haddon Heights, New Jersey, U.S.
Occupation	Basketball coach
Years active	1996–present
Known for	Assistant coach for the New York Knicks; head coach of Navy Midshipmen and Saint Joseph's Hawks

William Lange (born February 11, 1972) is an American basketball coach who currently serves as an assistant coach for the New York Knicks in the National Basketball Association (NBA). His previous head coaching roles include leading the Navy Midshipmen and the Saint Joseph's Hawks.

High school

A native of Haddon Heights, New Jersey, Lange played high school basketball at Bishop Eustace Preparatory School located in Pennsauken Township, New Jersey. He continued his playing career at the collegiate level with Rowan University. Lange’s coaching journey began at Bishop Eustace, where he succeeded his father for a single season, guiding the team to a 20–6 record and an appearance in the state championship game.

Coaching career

Lange initiated his college coaching tenure in 1996 as an assistant to Hall of Fame coach Herb Magee at Philadelphia University. After two years, he transitioned to Division I basketball in 1998, joining La Salle University as an assistant coach. During the 1998–99 campaign, he contributed to the Explorers achieving a 13–15 record before accepting the head coaching position at the United States Merchant Marine Academy in Kings Point, New York.

His initial head coaching seasons at the collegiate level were marked by considerable success. In his first year (1999–2000), Lange led the Mariners to a Skyline Conference regular season championship with a 17–11 overall record, narrowly missing qualification for the Division III NCAA Tournament. The subsequent season saw even greater accomplishments as his squad posted a 22–8 overall mark (15–1 in conference play), capturing both the regular season and conference tournament titles and advancing to the Division III Sweet 16—representing the deepest postseason run in USMMA’s history.

Afterward, Lange returned to Division I ranks as an assistant coach at Villanova University from 2001 through 2004 under head coach Jay Wright, during a period marked by notable team achievements.

In 2004, Lange secured his first Division I head coaching role at the United States Naval Academy in Annapolis, Maryland. Taking over a program that had finished 5–23 the previous year, he gradually improved their performance. By the 2007–08 season, he guided Navy to its first winning record in seven years with a 16–14 finish, followed by a 19–11 record in the 2008–09 campaign.

Lange returned to Villanova in May 2011 as associate head coach. After two seasons there, he transitioned to the NBA for the 2013–14 season, joining the Philadelphia 76ers as a player development coach. Before making this move, Lange declined a head coaching offer from the Rio Grande Valley Vipers, the NBA Development League affiliate of the Houston Rockets.

During his tenure with Philadelphia, Lange advanced into lead assistant roles concentrating on player development and offensive coordination. On March 28, 2019, he was named head coach of men's basketball at Saint Joseph's University, taking over from longtime coach Phil Martelli.

On September 10, 2025, Lange was appointed as an assistant coach for the New York Knicks.

Personal life

Lange is married to Alicia and they have four sons: Will, Matt, Marcus, and Jacob.