DAH may refer to:

• DAH (airline), the national flag carrier airline of Algeria
• DAH (language), a language in the Warup branch of the Finisterre family of Finisterre-Huon languages
• Destroy All Humans!, a video game
• Disordered action of the heart

Dah may refer to:

• The longer of the two symbols used in Morse code
• Dah, Ivory Coast, a village in Montagnes District, Ivory Coast
• Dah, Mali
• Dah (band), former Yugoslav/Belgian progressive rock band
• Destroy All Humans! (series), video game franchise

Destroy All Humans! is an action-adventure game developed by Pandemic Studios and published by THQ. It was released for PlayStation 2 and Xbox on June 21, 2005 in North America and June 24, 2005 in Europe. The game is set in 1959 in the U.S. and parodies the lifestyles, pop culture, and politics of this time period. The player controls Cryptosporidium 137 (a reference to the protozoan parasite Cryptosporidium), a member of the fictional Furon race of alien life, who has come to Earth to harvest DNA from humans to continue the cloning process of his species.