The history of the Boston Bruins professional ice hockey team dates back to 1924, making them the third-oldest active team in the National Hockey League (NHL), and the oldest surviving professional hockey franchise in the United States.

The Bruins are one of the Original Six NHL teams, along with the Detroit Red Wings, Chicago Blackhawks, Montreal Canadiens, New York Rangers and Toronto Maple Leafs. They have won six Stanley Cup championships, tied for fourth-most of any team with the Blackhawks (trailing the Canadiens, Maple Leafs, and Red Wings, with 24, 13, and 11, respectively), and tied for second-most for an NHL team based in the United States. The Bruins have also won four Presidents' Trophies, their win in 2023 featuring the Bruins with 135 points—the most in one season in NHL history.

The first facility to host the Bruins was the Boston Arena (now known as Matthews Arena), the world's oldest (built 1909–10) indoor ice hockey facility still in use for the sport at any level of competition. Following the Bruins' departure from Boston Arena, the team played its home games at the Boston Garden for 67 seasons, beginning in 1928 and concluding in 1995, when they moved to the TD Garden, their current home.

Early years (1924–1942) In 1924, as a result of the convincing of Boston grocery magnate Charles Adams, the NHL decided to expand to the United States. Adams had come to greatly enjoy ice hockey while watching the 1924 Stanley Cup Final between the NHL champion Montreal Canadiens and the Western Canada Hockey League (WCHL) champion Calgary Tigers. The previous year in 1923, sports promoter Thomas Duggan received options on three NHL franchises for the United States, and sold one of the options to Adams (Duggan would go on to found the New York Americans with another of the franchises), who in turn, persuaded the NHL to grant him a franchise for the city of Boston for $15,000, which occurred on October 13, 1924. With the Montreal Maroons, the team was one of the NHL's first expansion teams, and the first to be based in the United States. Adams' first act was to hire Art Ross, a former star player and innovator, as general manager. Ross was the face of the franchise for the next thirty years, including four separate stints as coach.

Adams directed Ross to come up with a nickname that would portray an untamed animal displaying speed, agility and cunning. Ross came up with "Bruins", a name for brown bears used in classic folk tales. The nickname also went along with the team's original uniform colors of brown and yellow, which were taken from Adams' grocery chain, First National Stores.

On December 1, 1924, the Bruins played their first NHL game, and the first NHL game played in the United States, against their expansion cousins the Maroons, at Boston Arena, with forward Smokey Harris scoring the first-ever Bruins goal, spurring the Bruins to a 2–1 win. This would be one of the few high points of the season, as the Bruins proved to be no match for the established NHL teams. The Bruins only managed a 6–24–0 record (to this day, their worst points percentage – .200 – in franchise history) and finished in last place. Within this timeframe, only one week later on December 8, 1924, what would become one of the NHL's all-time fiercest rivalries was initiated, as the Montreal Canadiens were the visiting team at the Boston Arena that night, defeating the hometown Bruins by a 4–3 score. The Bruins played three more seasons at the Arena, after which they became the main tenant of the newly built Boston Garden, while the old Boston Arena facility – the world's oldest existing indoor ice hockey venue still used for the sport at any level of competition, and the only surviving rink where an Original Six NHL team began their career in the league – was eventually taken over by Northeastern University, and renamed Matthews Arena when the university renovated it in 1979.

The Bruins managed to improve in their second season to a winning 17–15–4 record, but missed out on the third and final playoff berth by one point to the expansion Pittsburgh Pirates.Standings: The improvement to a winning record which originally held the record for the biggest single-season improvement in NHL history, and is now third.

In their third season, 1926–27, Ross took advantage of the collapse of the Western Hockey League to purchase several western stars, including the team's first great star, defenseman Eddie Shore. With the Bruins, he would go on to become one of the greatest players in NHL history. The Bruins' moves were largely counterbalanced by WHL player acquisitions by other NHL teams, and the team's record was actually slightly worse than the previous season, but Boston nevertheless qualified for the then-expanded playoffs by a comfortable margin. In their first-ever playoff run, the Bruins reached the Stanley Cup Final where they lost to the Ottawa Senators in the first Cup Final to be exclusively between NHL teams. The cup-winning game for the Senators would see Bruin Billy Coutu attack the referee, earning him a ban from the NHL for life, the only in league history.

The 1928–29 season was the first played at Boston Garden, which Adams had built after guaranteeing his backers $500,000 in gate receipts over the next five years. In 1929, the Bruins defeated the New York Rangers to win their first Stanley Cup. Standout players on the first championship team included Shore, Harry Oliver, Dit Clapper, Dutch Gainor and goaltender Tiny Thompson. The season after that, 1929–30, the Bruins posted the best-ever regular-season winning percentage in the NHL (.875, winning 38 of 44 games, a record which still stands) and shattered numerous team scoring records, but lost to the Montreal Canadiens in the Stanley Cup Final. The 1930s Bruins teams included Shore, Thompson, Clapper, Babe Siebert and Cooney Weiland. The team led the league's standings five times in the decade. In 1939, the team captured its second Stanley Cup. That year, Thompson was traded for rookie goaltender Frank Brimsek. Brimsek had an award-winning season, capturing the Vezina and Calder Trophies, becoming the first rookie named to the NHL first All-Star team, and earning the nickname "Mr. Zero." The team skating in front of Brimsek included Bill Cowley, Shore, Clapper and "Sudden Death" Mel Hill (who scored three overtime goals in one playoff series), together with the "Kraut line" of center Milt Schmidt, right winger Bobby Bauer and left winger Woody Dumart.

In 1940, Shore was traded to the struggling New York Americans for his final NHL season. In 1941, the Bruins won their third Stanley Cup after achieving an 27–8–13 record and finishing first in the regular season. It was their last Stanley Cup for 29 years. World War II affected the Bruins more than most teams; Brimsek and the "Krauts" all enlisted in the Royal Canadian Air Force following the 1941 Cup victory, and lost the most productive years of their careers at war. Cowley, assisted by veteran player Clapper and Busher Jackson, became the team's remaining star.

Original Six era (1942–1967) By 1942, the NHL had been reduced to the six teams that would be called the "Original Six", but on-ice talent was still depleted due to World War II.

In 1944, Bruin Herb Cain set the then-NHL record for points in a season with 82, more than double his previous career high. However, the Bruins did not make the playoffs that season, and while the next season, Cain was second in the league in goals with 32, the 1945–46 season—when demobilized soldiers began to return to the league—was his last, as he was unable to secure deals with any teams.

That same year, Dit Clapper led the team back to the Stanley Cup Final as player-coach. He retired as a player after the next season, becoming the first player to play twenty NHL seasons, but stayed on as coach. The next three seasons saw the Bruins make the playoffs each year—with two third place and one second-place finishes, respectively—but lose in the first round of the playoffs each time. One shocking development was the lifetime suspension of star young forward Don Gallinger in 1948 on suspicion of gambling on his own team to lose.

Several changes took place after the third such defeat in the 1948-49 season. While the returning Kraut Line of Schmidt, Dumart and Bauer continued their previous strong level of play post-war (in their first full year back, Schmidt was voted First Team All-Star at center, while Dumart and Bauer were both voted Second Team All-Stars), Brimsek did not, and was traded to the Chicago Black Hawks. Clapper stepped down as coach. The only remaining quality young player who stayed with the team for any length was forward Johnny Peirson, recognizable to fans of a later era as the Bruins' television color commentator in the 1970s.

During the 1948–49 season, the original form of the "spoked-B" logo, with a small number "24" to the left of the capital B signifying the calendar year in the 20th century in which the Bruins team first played, and a similarly small "49" to the right of the "B", for the then-current season's calendar year in the 20th century, appeared on their home uniforms—a nod to the Boston area's nickname of "The Hub". The following season, the logo was modified into the basic "spoked-B" form that was to be used, virtually unchanged (except for certain proportions within the logo), through the 1993–94 season.

The 1950s began with Charles Adams' son Weston (who had been team president since 1936) facing financial trouble. He was forced to accept a buyout offer from Walter A. Brown, the owner of the National Basketball Association's Boston Celtics and the Garden, in 1951. Although there were some instances of success (such as making the Stanley Cup Final in , , and , only to lose to the Montreal Canadiens each time), the Bruins mustered only four winning seasons between 1947 and 1967. They missed the playoffs eight straight years between 1960 and 1967.

In 1954, on New Year's Day, Robert Skrak, an assistant to Frank Zamboni, the inventor of the best-known ice resurfacing machine of the time, demonstrated a very early model of the machine at Boston Garden to the team management, and as a result, the Bruins ordered one of the then-produced "Model E" resurfacers to be used at the Garden, the first known NHL team to acquire one of the soon-to-be-ubiquitous "Zambonis" for their own use. The Bruins' Zamboni Model E, factory serial number 21—used as late as the 1980s on an emergency basis—eventually ended up in the Hockey Hall of Fame in Toronto in 1988 for preservation.

On January 18, 1958, a milestone in NHL history occurred as the first black person ever to play in the NHL stepped onto the ice for the Bruins, New Brunswick-born left wing Willie O'Ree. He played in 45 games for the Bruins over the 1957–58 and 1960–61 seasons, scoring six goals and ten assists in his NHL career.

During this period, the farm system of the Bruins was not as expansive or well-developed as most of the other five teams. The Bruins sought players not protected by the other teams, and in like fashion to the aforementioned signing of Willie O'Ree, the team signed Tommy Williams from the 1960 Olympic-gold medal-winning American national men's hockey team—at the time the only American player in the NHL—in 1962. The "Uke Line"—named for the Ukrainian heritage of Johnny Bucyk, Vic Stasiuk, and Bronco Horvath – came to Boston in 1957 and enjoyed four productive offensive seasons, heralding, along with scoring stalwarts Don McKenney and Fleming MacKell, the successful era of the late 1950s. There followed a long and difficult reconstruction period in the early to mid-1960s.

Expansion and the Big Bad Bruins (1967–1979)