Nye Frankie Newman, 17, from Aldershot in Hampshire, died in the French capital on New Year's Day.
Speaking at the memorial in Guildford, his mother Debs Malone told the crowd of teenagers to carry his spirit "forever".
A minute's silence was held at the event, organised by the Brewman parkour group Mr Newman co-founded.
His friends took part in a "remembrance jam" afterwards.
Ms Malone, 49, said: "Can I ask you all, please carry Nye's spirit with you forever and always, and smile.
"I want you all to put your hand on your heart now and we are going to get down for my boy.
"Stay safe, stay brave, stay strong yeah? And be happy."
Alex Grubb, 18, who helped to organise the event, described the teenager as kind, caring and "very eccentric".
He said: "He had his own style, he wasn't like anyone else. He was a bit out there, very opinionated but very loving at the same time."
Organisers estimated about 200 people attended the memorial.
Before the event, Guildford council and Surrey Police had warned businesses to take "reasonable measures to prevent rooftop access".
But organiser Luke Stones, 16, said: "We have had made it clear people should not go on rooftops.
"If they go on rooftops, it's not parkour, that's another sport. Today, we are sticking to ground level."
He said rooftop running was more usually referred to as urbex, climbing or roof-topping.
Mr Stones said people had travelled from across Europe and Hong Kong, where Mr Newman visited in the summer.
He said organisers could not comment on Mr Newman's death, but confirmed he "was not participating in parkour" at the time of the accident.
Guildford council said it provided Portsmouth Road car park as a meeting place for the memorial, but not as a place for free-running.
A statement said: "By providing an area for the memorial event, the council does not condone or encourage parkour or free-running in our car parks, properties or anywhere else in the town or borough, whether it is at a low level or on rooftops."
Mr Stones defended the activity and said: "It is another form of exercise.
"It is a way to express your emotions through movement.
"When you're doing parkour you're at one with yourself, it's almost like a meditation."
The UK this year became the first country to officially recognise parkour as a sport.

Speaking to reporters, FBI boss James Comey said the plans to enable encryption by default could thwart law enforcement investigations.
Lives could depend on police forces continuing to get access to the data on devices used by criminals and terrorists, he said.
The FBI was talking to both Apple and Google about its fears, said Mr Comey.
The conversations with tech firms needed to be had before the day when police forces lost access to those devices, he said.
"I'd hate to have people look at me and say, 'Well how come you can't save this kid?' 'How come you can't do this thing?'" said Mr Comey in a briefing.
His comments came in reaction to a decision by Apple to enable a file encryption system on its iOS 8 software for which it has no keys. This means it would not be able to comply with any official request to help police get at the data on those devices.
Google has said it too is planning to enable a similar encryption system by default on the next version of Android.
Mr Comey said he was "very concerned" about these plans because of what they would allow people to do.
"What concerns me about this is companies marketing something expressly to allow people to place themselves beyond the law," he said.
"I am a huge believer in the rule of law, but I am also a believer that no-one in this country is beyond the law," he added.
Apple and Google have yet to respond to Mr Comey's comments.
Ten days prior to Mr Comey's press statement, iOS data forensics expert Jonathan Zdziarski pointed out that Apple's encryption system would not stop police getting at data on portable devices.
Specifically weakening security systems just to aid the police was a bad decision, he said.
"For the sake of privacy and overall security, the only logical solution is to make products as secure as possible, and let good detective work do the crime solving, rather than an easy button," he wrote in a blogpost.
Free-runners gathered to remember a parkour enthusiast who died in an accident on the Paris Metro.
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Plans by Apple and Google to do more to protect customers' privacy have made the FBI "very concerned".