Red triangle (graphically 🔺 or 🔻) may refer to:

• Bass Brewery's "iconic red triangle" trademark, England's first registered trademark
• Red triangle (badge), a Nazi concentration camp badge worn upright by prisoners of war, and worn inverted for political prisoners
• Red triangle (Channel 4), British television content warning system symbol
• Red triangle (family planning), the symbol for family planning health and contraception services
• Red triangle (Palestinian symbol), a symbol used by the Palestinian militant group Hamas and pro-Palestinian protesters

• Red Triangle (Pacific Ocean), a shark-infested Pacific Ocean region off the northern California coast
• Red triangle slug, a species of land slug from Australia

• A symbol on the Brazilian state flag of Minas Gerais
• The alchemical symbol for Fire (classical element)
• The "Red Triangle Circus", a fictional gang in the film Batman Returns
• Red Triangle, the parent company of the Alvis Car and Engineering Company
• The Red Triangle, an area of Puebla state known for huachicolero activity (organized fuel theft)