Haha may refer to:

• An expression of laughing
• The sound of laughter
• Any of several species of Hawaiian plants, including many in genus Cyanea
• Ha-ha, a fence concealed in a ditch
• Human anti-human antibody
• Ha-Ha (street artist), Australian graffiti street artist
• Haha (entertainer) (born 1979), Korean entertainer
• Haha (Berber), a Moroccan Berber ethnic group
• Ha Ha!, catch phrase of character Nelson Muntz from the series The Simpsons
• Raleigh, Newfoundland and Labrador, formerly known as Ha Ha Bay
• Haha-jima, an island of Japan
• Hahaha (film), a 2010 South Korean film