The Buick LaCrosse is a mid-size car produced by the Buick division of American automaker General Motors since 2004 as the 2005 model year. The LaCrosse, only available as a four-door sedan, replaces the Century and Regal models of Buick's lineup. Its namesake is the Buick LaCrosse concept car shown beginning in 2000. The original name was inspired by a Buick concept car of the same name shown in 2000 and also used as a reference to the sport of lacrosse, seen as popular with a younger, more active demographic to which Buick sought to market. However, la crosse means masturbation or swindling in Quebecois slang, so it is sold as the Buick Allure in Canada.

The next-generation LaCrosse, coming as a 2010 model, is to be built upon the future GM mid-size platform, Epsilon II. It is to be heavily based on the 2008 Buick Invicta concept and it is unknown whether the new vehicle will remain under the Lacrosse name or go under the Invicta nameplate. The 2010 LaCrosse will make its debut at the 2008 Los Angeles Auto Show in November 2008.