The Boston Celtics franchise has been around for quite a long time. Its first season as a pro team came all the way back in the 1946-47 season when the NBA was called the Basketball Association of America or BAA.

The Celtics are one of the most successful franchises in North American pro sports. The team has won a whopping 17 NBA titles — tied with the Los Angeles Lakers for the most of any team in the league — and has made it to the NBA Finals 22 times. Boston's most recent NBA Finals appearance was in 2022 when it lost to Stephen Curry, Klay Thompson, and the Golden State Warriors in six games.

Considering all of the success that the Celtics franchise has enjoyed over its seven-plus-decade existence, it should come as no surprise that the Celtics have plenty of terrific trades. Some of the best players in franchise history were acquired via trade, such as Kevin McHale, Robert Parish, Kevin Garnett, and Ray Allen, just to name a few.

With all of that being said, let's rank the five best trades in the history of the Boston Celtics franchise:

5. Celtics acquire Isaiah Thomas

Shortly before the 2015 NBA Trade Deadline, the Celtics traded Marcus Thornton and a 2016 first-round via the Cleveland Cavaliers in exchange for diminutive Phoenix Suns point guard Isaiah Thomas. Thomas spent just two and a half seasons with the Celtics, but in this short time, he established himself as a Celtics legend.

Thomas accomplished a whole lot with the Celtics, both from an individual and collective standpoint. He made two All-Star appearances and one All-NBA appearance during his time with Boston. And the Celtics made the postseason every year Thomas was on the team, and they even made it all the way to the Eastern Conference Finals in 2017, where they lost to LeBron James and the Cleveland Cavaliers.

Thomas' best season with Boston was, without a doubt, the 2016-17 season. The 5'9″ point guard averaged a career-high 28.9 points per game during the regular season while shooting 46.3% from the field and 37.9% from behind the three-point arc.

His regular season was historic from a scoring perspective. Thomas' 28.9 points per game average marks the third-highest  regular-season scoring average of any player in Celtics history, behind only Larry Bird (who averaged 29.9 points per game during the 1987-88 regular season) and Jayson Tatum (who averaged 30.1 points per game during the 2022-23 regular season).

4. Celtics acquire Ray Allen

In the summer of 2007, the Boston Celtics traded Delonte West, Wally Szczerbiak, and the fifth overall pick in the 2007 NBA Draft (Jeff Green) to Seattle for Supersonics sharpshooter Ray Allen. The Celtics soon after traded for big man Kevin Garnett to form a big three in Boston.

Allen was the most underrated player of the Celtics' big three. Across his five seasons in Boston, Allen received three All-Star nods and played in 73 regular-season games or more in all but one season.

Allen's best season as a Celtic came during the 2008-09 season when he averaged 18.2 points per game during the regular season and shot 40.9% from behind the three-point arc. The Celtics seemed prime to compete for a title in the 2009 playoffs, but Garnett injured his knee in February of that year, and the Celtics lost to the Orlando Magic in the second round of the postseason.

Some Celtics fans still have bitter feelings toward Allen, considering he left the Celtics for the Miami Heat in free agency in the summer of 2012, but Cs fans should remember Allen fondly and as an invaluable piece to the Boston team that went on to win the NBA title in 2008.

3. Celtics acquire Kevin Garnett

Also in the summer of 2007, the Celtics traded Al Jefferson, Ryan Gomes, Gerald Green, Sebastian Telfair, Theo Ratliff, and a pair of first-round picks to the Minnesota Timberwolves and received star big man Kevin Garnett in return. The Celtics gave up a lot for Garnett, as they traded five players and two first-round picks for him, but Garnett proved to be well worth the price.

Garnett spent six seasons as a member of the storied Celtics franchise. He made the All-Star team in five of his six seasons in Boston and won the 2007-08 Defensive Player of the Year award.

Garnett's best season as a Celtic was during his first season with the team, the 2007-08 campaign. He averaged 18.8 points, 9.2 rebounds, 3.4 assists, 1.4 steals, and 1.3 blocks per game across 71 appearances during the regular season (all starts). And Garnett rose his play to an even higher level during the 2008 playoffs, particularly in the NBA Finals against the Los Angeles Lakers. Garnett averaged 18.2 points and 13.0 rebounds per game for the series, and the Celtics went on to win in six games, though Paul Pierce received the Finals MVP award.

2. Celtics trade Paul Pierce and Kevin Garnett to the Brooklyn Nets

In the summer of 2013, the Celtics traded Paul Pierce, Kevin Garnett, Jason Terry, and DJ White to the Brooklyn Nets for Kris Humphries, Gerald Wallace, Kris Joseph, Keith Bogans, MarShon Brooks, three first-round picks, and two pick swaps. At the time, the trade garnered mixed opinions from Celtics fans, as some believed Boston didn't get enough valuable assets in return. But fast forward to the current day, and it's clear that this trade was one of the best in Celtics history.

The Nets were one of the worst teams in the entire league in the 2015-16 and 2016-17 seasons. As a result, the Celtics received the third overall pick in the 2016 NBA Draft and the first pick in the 2017 NBA Draft (which Boston used to trade down to the third pick). The Celtics used their 2016 Nets pick on Jaylen Brown and their 2017 pick on Jayson Tatum.

Brown and Tatum have accomplished a whole lot during their six seasons and counting as teammates. They have led the Celtics to the Eastern Conference Finals four times and led them to the NBA Finals once, back in 2022. And if it weren't for the Nets trade that the Celtics made a decade ago, the Celtics would have never had the opportunity to draft Tatum or Brown.

1. Celtics trade for Robert Parish and Kevin McHale

In the summer of 1980, Red Auerbach orchestrated the best trade in Celtics franchise history. He dealt two first-round picks to the Golden State Warriors in exchange for big man Robert Parish and a draft pick that became Kevin McHale.

Parish, McHale, and Larry Bird formed arguably the greatest frontcourt trio in the history of basketball. During their time together, they won three NBA titles — in 1981, 1984, and 1986 — and made it all the way to the NBA Finals five times.

Robert Parish spent a whopping 14 seasons with Boston, from the 1980-81 season to the 1993-94 season. He served as a two-way star for Boston, as he averaged 16.5 points, 10.0 rebounds, and 1.5 blocks per game across 1106 total regular-season appearances with the Celtics (1093 starts). His best season as a Celtic came during the 1981-82 season when he averaged 19.9 points, 10.8 rebounds, and 2.4 blocks per game during the regular season and was named to the All-Star team.

Kevin McHale spent all 13 seasons of his NBA career playing for the Celtics. McHale earned seven All-Star appearances, six All-Defensive team nominations, and two Sixth Man of the Year awards during his time with Boston. His best season with the Celtics came during the 1986-87 season, as he averaged a career-high 26.1 points to go along with 9.9 rebounds and 2.2 blocks per game across 77 regular-season appearances. McHale also led the league in field-goal percentage during that regular season — he converted 60.4% of his field-goal attempts.

If the Celtics didn't make that trade for McHale and Parish back in the summer of 1980, it's possible that they wouldn't have won a title in the decade, even with Larry Bird on the roster.