The 1975 NBA World Championship Series was the championship round of the 1974–75 NBA season of the National Basketball Association. The Golden State Warriors (48-34) of the Western Conference played against the Washington Bullets (60-22) of the Eastern Conference. The series was played under a best-of-seven format.
The Warriors' home games were played at the Cow Palace in Daly City (near San Francisco) due to scheduling conflicts at their normal home court of Oakland Arena during the week of May 19–26. In addition, an odd scheduling format had to be used because Golden State could not secure the Cow Palace for Memorial Day Weekend (May 24–26). A Sports Illustrated article about the series reported that Washington, which held home court advantage, was given the option of a 1-2-2-1-1 scheduling format due to Golden State's problems or, if they wished, opening on the road and then having Games 2, 3, and 4 at home. Washington opted for the 1-2-2-1-1 format not out of a sense of fairness, but because they wanted to open the series at home.
The series is notable as it was the first championship game or series in any of the four North American major professional sports leagues to feature two African American head coaches or managers, as Al Attles coached the Warriors and K. C. Jones coached the Bullets. On a lesser note, it was the first time that the NBA ever scheduled a game to be played in the month of June (Game 7 was scheduled for Monday Night, June 2). The first June game ever, however, would have to wait until the following year.
The underdog Warriors won four games to earn a sweep over the Bullets.
The Golden State Warriors last made the NBA Finals in 1967, when they were still in San Francisco. In the years since, they moved to Oakland, briefly lost Rick Barry to the American Basketball Association, and named Warriors great Al Attles as head coach. Before the start of the 1974–75 season they traded future Hall of Famer Nate Thurmond to the Chicago Bulls for young center Clifford Ray. They also drafted Jamaal Wilkes, then known as Keith Wilkes, out of UCLA. With Barry as the offensive leader, and with Attles using a team approach to coaching, the Warriors managed to finish the season atop the Western Conference with 48 wins. In the playoffs, they defeated the Seattle SuperSonics in six games, then eliminated Thurmond and the Bulls in seven games to advance to the Finals.
The Washington Bullets were in their second season in the Washington Metropolitan Area, having moved from Baltimore prior to the 1973–74 season. The Bullets, led by Wes Unseld and Elvin Hayes, and coached by K. C. Jones, won 60 games that season, then overcame the Buffalo Braves and the defending champion Boston Celtics in seven and six games, respectively. The Bullets franchise headed to their second NBA Finals appearance, the last of which was a sweep by the Milwaukee Bucks in 1971.
Washington won the regular season series 3–1.
Golden State Warriors defeated Washington Bullets, 4 games to 0.
Opting to open the series at home, the Bullets built a 14-point lead at the half over the Warriors at the Capital Centre. The Warriors began to storm back, with Phil Smith coming off the bench to score 20 points in 31 minutes of playing time, as Golden State took the first game, 101-95. 
Instead of their familiar Oakland Coliseum Arena, the Warriors were forced to play their first two scheduled home games of the series at the nearby Cow Palace (the Oakland facility being unavailable). The Bullets jumped to an early 13-point lead, but Golden State battled back, led by 36 points from Rick Barry, to take a 92-91 lead in the closing seconds. Washington got the ball back with six seconds left but missed two shots and now were down 2-0. 
Rick Barry poured in 38 points and backup center George Johnson had 10 points and nine rebounds off the bench to help the Warriors to a key Game 3 109-101 win.
Two major factors enabling the Warriors to take an insurmountable lead were the defensive play of the seemingly undersized Jamaal Wilkes on Bullets' power forward Elvin Hayes and the play of the Warrior bench. In three games, Hayes had only 29 points and the Warriors' bench players had outscored the Bullets' reserves 115-53. 
Back at home, the Bullets seemed to be on their way to staving off an unexpected sweep by the underdog Warriors, leading by 14 points early on. Bullets forward Mike Riordan was assigned to guard Barry, who had killed the Bullets in the series up to that point by averaging 35 points a game. Riordan played Barry very physically, arousing the ire of Warriors' coach Al Attles. Midway through the first quarter, Barry went on a drive to the basket and was fouled hard from behind by Riordan. Barry reacted with a shove, but Attles bolted onto the court and initiated a fight of his own with Riordan, thereby protecting his star player from an ejection and getting ejected himself. The remainder of the game was directed by assistant coach Joe Roberts.
After the brawl, Barry immediately went on a scoring tear, but had to endure boos and taunts from the Capital Centre crowd. His performance, along with the Warriors' pressure defense, brought them back and guard Butch Beard scored the last seven points of the game, including two free throws to make the final score 96-95. 
The Washington Bullets would appear in the NBA Finals in 1978 and 1979 against the Seattle SuperSonics, with a series win in seven games and a series loss in five games respectively.
The Golden State Warriors would win their next championship 40 years later in 2015 against the Cleveland Cavaliers in six games, ending the longest drought between championships in NBA history.