Five other people were also wounded in the shooting, including a 13-year-old girl, a 16-year-old boy and two other 17-year-old boys.
Police have said that Davis and some of the other victims were innocent bystanders. Officers have located at least 100 shell casing in the area.
His family said Davis was walking towards his home to put on shoes to go to his father's place when gunfire erupted.
Interim Peel Regional Police Chief Chris McCord said Sunday that the perpetrators were motivated by a rap video filmed in the same parkette earlier this month that challenged "other people within the community."
"Jonathan was my right hand," his father Linton Davis said during the vigil.
Linton said his son, who he named after a character from the Bible, was an extraordinary kid.
Selma Alincy, who is a family friend, describes Davis as a smart, loveable, kind person.
"He wanted to be an electrician, and his life was taken too soon," Alincy said.
Bluez, a local activist and co-organizer, said the vigil is a way to unite the community and begin the healing process.
"I think this is just the beginning of some sort of closure. It initiates some sort of process where we're able to talk," he said.
"We're not going to stop living our lives."
Bluez said there needs to be more funding for social programming that will keep kids away from dangerous activities.