Hundreds of people of all faiths gathered for food, fellowship and understanding.
Earlier this week, vandals through a pig's head from a pickup truck in front of the mosque.
The pot-luck gathering aimed to counter the anti-Islamic sentiment since the terror attacks in Paris and California.
Derek Dorsey of South Kensington isn't Muslim, but he helped organize the event.
"It really hit home with me, and I felt we needed to do something as a community to show the city and show the nation that we stand together as one," said Dorsey.
"There's a huge amount of support happening, which is great. It's really refreshing to see," said Sarah Gardner of Fishtown.
During the event, Islamic, Christian and Jewish leaders led the group in prayer.
Some non-Muslims even learned how to wear a Hijab.
Those in attendance mixed and mingled, then shared a meal.
Organizers hope teaching about Islam can counter misconceptions.
"Terror, scared of and we should be afraid of, and it's being perpetrated even by our own politicians," said Dorsey.
"I think some people express their fear in really unfortunate ways, and I think it's important to be reminded by those moments to come out and express our support," said Gardner.
Philadelphia police and the FBI are investigating the incident at the mosque.
A $4,000 reward is being offered for information leading to the arrest and conviction of the persons responsible. PETA and Mayor Michael Nutter each posted $2,000.
Anyone with information about the incident is encouraged to contact the Philadelphia Police Department tip line at 215-686-8477.