The Milwaukee Bucks were formed in January 1968 when the NBA awarded a franchise to Milwaukee Professional Sports and Services, Inc. (Milwaukee Pro), a group headed by Wesley Pavalon and Marvin Fishman. In October, the Bucks played their first NBA regular season game against the Chicago Bulls before a Milwaukee Arena crowd of 8,467. On April 30, 1971, the Bucks won Game 4 of the NBA Finals over the Baltimore Bullets in Milwaukee 118-106, to win the NBA Championship. The championship was won faster than by any other expansion team in professional sports history (3rd season). In 1972, the Los Angeles Lakers had their record 33-game winning streak snapped by the Bucks during a nationally televised game, and in 1973 the Bucks recorded their third consecutive 60-win season, the first NBA team to do so.

In 1985, Milwaukee businessman (and now U.S. Senator) Herb Kohl bought the Bucks after fears that out-of-town investors could buy the team and move it out of Milwaukee. In 2003, after considering selling the team, Kohl announced that he had decided against selling the Bucks to Michael Jordan and would "continue to own them, improve them and commit them to remaining in Wisconsin."

In the 1988-89 season, after 20 years at the 11,052-seat MECCA (Milwaukee Arena, now U.S. Cellular Arena), the Bucks moved into the new 18,600-seat Bradley Center, located directly across the street from the MECCA in downtown Milwaukee. The Bradley Center was one of the first arenas in the country to be built with luxury suites. The Bradley Center was privately financed from a $90 million donation from Milwaukee businesswoman Jane Bradley Pettit in memory of her father.

In the 2004-2005 season, plagued with injury problems and a poor defense, the Bucks missed the postseason with a 30-52 record. However, despite only having a 6 percent chance for one of the first three draft picks in the NBA Draft Lottery, the Bucks won the first pick for the 2005 NBA Draft. They used the first pick to select Andrew Bogut of the University of Utah.