With its inaugural season in 2009, water polo is a relatively new addition to Brunswick’s successful interscholastic sports programs. 

Nonetheless, competing in the New England Preparatory School Athletic Council against more established programs such as Exeter, Andover, Deerfield, Loomis Chafee, Choate and others, Brunswick’s water polo players have won the last nine NEPSAC championship titles. In addition to playing local East Coast power Greenwich High School, Brunswick has successfully competed in tournaments such as the Beast of the East (Wilson High School, Pa.), the Cardinal Cup (Greenwich High School, Conn.), the Santa Barbara Invitational (Calif.), the North-South Tournament (Calif.), the Elite Eight (Calif.) and the Next Generation Cup (Barcelona, Spain). 

Brunswick's skilled players and team play has gained national recognition with the program recently being ranked as high as fourth in the country – the only non-California team at the time in the top 20 to gain that honor. In 2024, Brunswick is currently ranked eighth in the country. On an individual player level, Brunswick has produced numerous NISCA Water Polo All-Americans, as well as placed boys on the USA Water Polo regional and national Development, Cadet, Youth, Junior and Senior teams. Players have gone on to compete at the collegiate varsity level at schools such as Stanford, Princeton, Harvard, Brown, MIT, and the U.S. Naval Academy. Many others continued to play and lead their college club teams to conference championships and to play at the National Collegiate Club Championships.

The Bruins compete at the Mehra Natatorium on Edwards Campus, where interscholastic water polo is also offered at the Middle School level.