Brian Lake (born 27 February 1982), born Brian Harris, is an Australian rules footballer, currently playing for the Western Bulldogs in the Australian Football League (AFL).

Picked late in the 2001 AFL Draft at pick 71 from Woodville West-Torrens, Lake was a relatively late developer. Making his AFL debut late in the 2002 season, he was seen as a raw full-back who was some way from fully developing.

However, by the 2005 season, Lakes' jobs in blanketing some of the best full-forwards in the game were seen as outstanding. He had come of age and shown significant improvement, much like many other of his Western Bulldogs teammates (such as Daniel Giansiracusa, Robert Murphy and Dale Morris), which led the team to within half a game of a finals berth.

After a two-week suspension in 2006 which resulted in him missing the first two premiership matches, Lake made his return against St. Kilda, where he was given the job on Fraser Gehrig.

In 2007 he developed into one of the best full-backs in the competition. His 2007 season will be remembered for the match against St. Kilda where he held two time Coleman Medal winner Fraser Gehrig to no possessions for the entire match.