Those at the vigil said they were calling for safer roads for delivery drivers in Dublin and for those responsible for Mr Cortes death to be caught.
Demonstrators said that many Deliveroo workers are unrecognised immigrant workers who face dangerous road conditions.
Teresa Dontas, Mr Cortes' fiancée, was joined by friends, cyclists and Deliveroo cyclists at the demonstration on O’Connell street.
Mr Cortes, who is from Brazil, died after he was struck by a car which failed to stop on North Wall Quay on Tuesday night.
Adriana Queiroz, a housemate of Mr Cortes, said they were hopeful that a Garda investigation would find those who fled the scene.
“I am here because he was my friend. He was a good, good man,” she said.
Ms Dontas, his fiancée, initially tried to talk to speak to the media but became too upset.
Friends of Mr Cortes said that while his partner's family were travelling over from Brazil, his mother did not have a passport and so was unable to come to Ireland.
Crowds prayed for Mr Cortes while those who knew him cried and embraced. Dozens of Deliveroo workers attended the protest in their uniforms. A number of delivery drivers, not affiliated with Deliveroo, also attended in solidarity.
Carina Jesus, a 24-year-old Brazilian woman who attended the vigil, said she had been working for Deliveroo for five months. Ms Jesus, who is working part time while she studies in Dublin, said that working as a Deliveroo cyclists was a popular job for foreign students or migrant workers. She said the job can be particularly dangerous in Dublin on weekends or during large tourist events.
“The roads are not safe. Sometimes cars will come right on top of you, far too near. It needs to be made safer, not just for Deliveroo cyclists but for all cyclists,” Ms Jesus, who was holding a bouquet of sunflowers for Mr Cortes, said.
“Deliveroo is a popular job because it is more flexible for students. It’s also an easier job to get for people who might not have paperwork. It needs to be safer.”
One Deliveroo driver, who asked not to be named, said that he had been worried for a long time that one of his colleagues would lose their lives on the roads in Dublin.
“I was afraid that something like this would happen. The work is dangerous,” he said.
Filipe Loyola, who has been working for Deliveroo for two years, was handing out copies of apology letters which were being given to the public Deliveroo workers.
“I’m a delivery rider writing to apologise, but first of all I’m going to introduce myself. There is no need to identify myself now since I’m here to represent many other immigrants,” the letter said.
“I’m the one who delivers your food, but what you do not know I will tell you now.”
The letter said delivery drivers wake up early, pray before leaving for work and deliver food while facing traffic, impatient drivers, and freezing cold weather.
“Today I apologise. I couldn’t get to your house. I got hit by a car, for no reason. I didn’t have time to think or stop. The situation took my life from me and my family and your food tonight I couldn’t deliver to you. I’m sorry,” the letter said.
“Dedicated to Thiago Osorio Cortes, Brazilian, husband, friend, Deliveroo and to his family and friends and many others who are not seen or recognised out there.”