Portland joined the NBA as an expansion franchise in 1970 and, within seven years, won its only championship, defeating the Philadelphia 76ers in the 1977 Finals behind coach Jack Ramsay and center Bill Walton, whose dominant, injury-shortened MVP season defined that title run. The Blazers remained competitive through the late 1970s and early 1980s but did not return to the Finals until the end of that decade, when a roster built around Clyde Drexler, Terry Porter, and later the addition of European star Arvydas Sabonis reached back-to-back Finals in 1990 and 1992, losing both times to eventual champions in Detroit and Chicago.

The late 1990s and early 2000s brought a talented but turbulent roster nicknamed the "Jail Blazers" by media and fans, a stretch that damaged the franchise's reputation despite continued playoff appearances. A pair of high-profile draft decisions, selecting Sam Bowie over Michael Jordan in 1984 and Greg Oden over Kevin Durant in 2007, became lasting points of franchise history as those passed-over players became stars elsewhere. The 2010s and 2020s were defined instead by guard Damian Lillard, whose long tenure produced repeated playoff appearances and division titles but no return trip to the Finals; ownership of the team changed in 2026, when Tom Dundon completed a purchase of the franchise from the estate of longtime owner Paul Allen.