David Paden Marchand (born David Paden Passaro, November 20, 1975), known professionally as Davey Havok, is an American singer who is the lead vocalist of the rock band AFI, the synth-pop band Blaqk Audio, the hardcore punk band XTRMST, and the new wave band Dreamcar. Among various other ventures, he performed lead vocals for Son of Sam's debut album and for fictional band My Purple Agony in the animated series Harvey Girls Forever!.

Havok is an advocate of the straight edge lifestyle and veganism.

Havok was born David Paden Passaro, in Rochester, New York on November 20, 1975. He is of Italian ancestry.

When Havok was age 5, his father died, and he and his mother moved from Rochester to Sacramento, California to be closer to family. His mother remarried and Havok took on the surname of his stepfather (Marchand), and was enrolled in Catholic school through eighth grade. The family moved to Ukiah, California in the late 1980s, where he graduated from Ukiah High School in 1993.

Following high school, Havok attended University of California, Berkeley. Following his sophomore year, his career with AFI started, and Havok did not return to the university.

Havok and his friends, Mark Stopholese and Vic Chalker, decided to start a band in high school, but they did not own or play any instruments. Stopholese suggested that Adam Carson might be able to fill the role of drummer because he owned a drum set. That band became AFI.

After high school, the band broke up when its members left for college. Havok attended UC Berkeley. There, he began writing lyrics that later appeared on AFI's first two albums.

After gaining some popularity in their absence, AFI played a show at the Phoenix Theater for several hundred fans. Following the positive reception, they decided to reunite and record an album. In 1995, Answer That and Stay Fashionable, the band's first album, was released on Wingnut Records and in 1996, Very Proud of Ya was released on Nitro Records. In 1997, the band released Shut Your Mouth and Open Your Eyes.