The Mann Cup is Canada's national Senior A men's box lacrosse championship, contested between the playoff champion of Ontario's Major Series Lacrosse and the champion of British Columbia's Western Lacrosse Association.

Played each September, the Mann Cup brings the champions of Canada's top traditional Senior A leagues together in an East-vs.-West championship series. The winner becomes Canada's Senior A men's box lacrosse champion.

For fans familiar with the National Lacrosse League, Senior A is not another name for the NLL. It is Canada's elite summer club classification. However, there is significant crossover between the two, with many Senior A stars also playing or having played professionally in the NLL.

Is The Mann Cup Box Lacrosse?

Yes. The modern Mann Cup is a box lacrosse championship, meaning games are played inside an enclosed arena rather than on a traditional outdoor lacrosse field.

Box lacrosse typically is played on a hockey-sized floor surrounded by boards. There are six players per team on the floor — five runners and one goaltender — and a 30-second shot clock keeps possessions moving quickly.

Interestingly, the Mann Cup is actually older than box lacrosse itself.

The trophy dates to 1910, when Sir Donald Mann donated it for senior lacrosse competition. Early Mann Cups were played as field lacrosse. The 1931 championship was the last played under field lacrosse rules before the indoor era began in 1932.

Who Plays For The Mann Cup?

The Mann Cup matches the champions of Canada's two major Senior A men's box lacrosse leagues.

In Ontario, teams compete in Major Series Lacrosse, commonly called MSL. The winner of the MSL playoffs advances to the Mann Cup as the Eastern representative.

In British Columbia, teams compete in the Western Lacrosse Association, or WLA. The WLA playoff champion advances as the Western representative.

That creates a straightforward path to the national championship: MSL champion vs. WLA champion for the Mann Cup.

How Does The Mann Cup Work?

The Mann Cup is played as a best-of-seven series. The first team to win four games becomes champion.

Unlike playoff series in leagues where teams travel between home cities, the Mann Cup is held entirely in one host region. Hosting alternates between Ontario and British Columbia rather than using a neutral site.

That means the visiting champion can spend the entire series playing away from home. The championship can last as few as four games or as many as seven.

Why Is The Mann Cup Important?

The Mann Cup has been part of Canadian lacrosse for more than a century.

Sir Donald Mann donated the trophy in 1910, and the competition evolved from its early challenge-trophy and field lacrosse roots into the national Senior A box lacrosse championship played today.

Its history includes some of the sport's great championship runs. New Westminster won six consecutive Mann Cups from 1920-25 during the pre-box era. Peterborough won four straight indoor championships from 1951-54. Six Nations produced a three-peat from 1994-96 and another from 2023-25.

New Westminster holds the leading historical total with 24 Mann Cups.

The series MVP also receives the Mike Kelley Memorial Trophy, which was first awarded in 1941.

Why Does The Mann Cup Still Matter?

The Mann Cup connects the history of Canadian lacrosse with the modern box game.

Many Senior A players also compete in the NLL, giving professional lacrosse fans an opportunity to see recognizable players competing for different summer clubs and for a championship with roots stretching back generations.

The event also preserves one of the simplest championship structures in the sport: Ontario against British Columbia, East against West, with four wins deciding Canada's Senior A champion.

The Mann Cup's significance also sits within the much longer history of lacrosse itself. The sport has Indigenous origins and deep significance among Haudenosaunee and other Indigenous peoples, predating the Mann Cup, Canadian governing bodies and modern professional leagues.

More than a century after the trophy was first contested, the Mann Cup remains a meeting point between that broader lacrosse tradition, Canada's elite summer box game and many of the players recognizable to today's professional lacrosse audience.