Police say Nyeme Taylor was shot six times by one of five teenagers who had earlier assaulted his 14-year-old son.
Taylor was transported to Temple University Hospital where he was pronounced dead.
It happened at a street party around 9:00 p.m. outside the Mander Recreation Center at 33rd and Diamond streets in North Philadelphia.
Police say Taylor got involved when he saw the teens attacking his son.
"The father went and he started pulling the kids off of his son. During that time, one of these males pulled out a gun and just started firing into the crowd," Captain James Clark of the Philadelphia Police Department said.
Police say Taylor's 15-year-old daughter was also wounded and two other girls, ages 6 and 10, were shot in the face.
"We need the public's help. It doesn't help us if we allow shooters to be on the loose," Philadelphia Police Commissioner Charles Ramsey said.
Anyone with information is asked to contact Philadelphia police.