Dantley attended the University of Notre Dame, where he played for three seasons before leaving after his junior year to enter into the NBA Draft under the old "hardship" rule.
As a freshman, he was part of the Fighting Irish squad in 1973 that upset UCLA to end the Bruins' record 88-game winning streak.
As an All-American selection with Notre Dame, he was a top scorer for Notre Dame in each of his three seasons there averaging around 25 points and 10 rebounds per game. Dantley was named National Player of the Year in 1976.
He also led the U.S. Olympic team to a gold medal at the 1976 Olympics in Montreal, ranking first on the team in scoring with a 19.3 points per game average.
Dantley was drafted as the sixth overall selection in the 1976 NBA Draft by the Buffalo Braves. He played just one season for the Braves, although Dantley made it count by averaging 36.1 minutes, 20.3 points and 5.9 rebounds per game. With his impressive stat line, Dantley was named NBA Rookie of the Year.
After his highly touted rookie year with Buffalo, Dantley was traded along with Mike Bantom to the Indiana Pacers for Billy Knight on September 1, 1977. He played in just 23 games for the Pacers averaging more than 25 points per game before he was once again traded -- this time to the Los Angeles Lakers for James Edwards, Earl Tatum and cash considerations on December 13, 1977.
Dantley teamed up with future Mavs teammate Brad Davis in Los Angeles, where he averaged around 20 points per game in his year and a half stay. In 1978-1979, he led the NBA for the first of four times in free throws made with 341. After that season, the Lakers traded Dantley to the Utah Jazz for Spencer Haywood on September 13, 1979 -- Dentley would spend his best years in Utah and played a total of seven seasons for the Jazz.
Dantley averaged 30 points or better in four seasons with Utah and was selected to All-Star teams in six of his seven seasons while a Jazz member missing only the 1982-1983, in which he played only 22 games, due to torn ligaments in his right wrist.. In his first all-star appearance in 1979-1980, he scored 23 points for this Western Conference team.
He returned from the injury to win the NBA scoring title in 1983-1984, averaging 30.6 ppg, and was named the league's Comeback Player of the Year.
Despite his success in Utah, Dantley was traded to the Detroit Pistons along with 1987 and 1990 second-round draft picks on August 21, 1986 for Kelly Tripucka and Kent Benson. During just over two seasons with the Pistons, Dantley helped lead the team to back-to-back Eastern Conference Finals appearances and an NBA Finals appearance in 1988, in which the team lost to the Lakers in seven games.
After two years of service to the Pistons, Dentley was then traded to the Mavs along with a 1991 first-round draft pick for Mark Aguirre.
Dantley played one and a half seasons for the Mavs, averaging around 17 points over his 76 games. Although he never helped lead Dallas to the playoffs, which in some ways ushered in the low times of the 1990s era for the Mavericks, Dantley is still regarded as one of the most talented players to ever come through the organization. A broken right fibula in February of 1990 ended Dantley's Dallas career.
He shopped his services for the 1990-1991 season but found no takers until the late in the year when he signed with Milwaukee and appeared in ten games averaging 5.7 ppg. He retired, after his stint with the Bucks, as the ninth all-time leading scorer in National Basketball Association history with 23,177 points.
Dantley played one final year, in Italy for Breeze Milan, averaging 26.7 ppg before moving back to the States and taking an assistant coaching position with Towson State.
He had his jersey number 4 retired by the Utah Jazz on April 11, 2007 and the following year was honored with induction to the Naismith Memorial Basketball Hall of Fame.
Dantley was back in the NBA as an assistant coach with the Denver Nuggets, under George Karl, for several seasons. He is currently retired and working as a crossing guard and basketball referee at his high school alma mater, DeMatha Catholic, in Washington D.C.