The Underground barbecue (BBQ-U) is a social activity whose concept's creation belongs to seven young men from Longueuil, Canada.

Taking the form of a special event, the nature of the Underground barbecue has yet to be completely defined. Essentially, it consists in a gathering of people who eat rare meat or special meals cooked on the grill and served in an unconventional way. During the Barbecue, the people organize and participate in activities, who are generally favorizing creativity. Those can be, but are not limited to, dances and music of all styles, speeches, alcohol or drugs-related activities, prayers, writing of poems, drawings and other form of visual arts or debates.

Generally, the Barbecue Underground must happen in a dark environment, favourable to the production of alternativemoods and ideas. As of 2005, the concept is still in its experimental stages and the definition can be refined following experience gaining and the progressive organisation of a larger number of Underground barbecues.