Some 500 people turned up at a Hong Lim Park event yesterday to rally for teenage blogger Amos Yee's release.
Five people spoke at the protest, which was organised by Community Action Network (CAN), a local non-governmental organisation.
CAN member Jolovan Wham, one of the speakers, said: "We're taking a stand against the Government's crackdown against Amos. Expressing a point of view is not wrong, unless you're doing it to incite violence. Amos' words did not cause any physical harm.
"He shouldn't even be charged."
Another speaker, Reverend Miak Siew of Free Community Church, said: "Someone from the crowd interrupted me before I started just now - do you forgive Amos Yee? "I replied what's there to forgive? What is there to forgive when I am not offended?
"Amos is a 16-year-old boy. He just said things we may not agree with, and some of us agree with him but disagree with how he said it. What harm has he caused other than a few ruffled feathers?"
Yee was found guilty in May of making remarks intending to hurt the feelings of Christians in an expletive-laden video, and uploading an obscene image.
He has been remanded for more than 50 days since, spending the past two weeks at the Institute of Mental Health for psychiatric examinations. He is due to be sentenced today.
"If we are to be a more resilient society that embraces diversity, then we have to learn how to react in a more mature manner instead of reporting to the police or threatening Amos with violence," said Mr Siew.
The other speakers at the event, which lasted more than an hour, were Ms Braema Mathi, president of rights group Maruah, activist Jolene Tan and Ms Teo Soh Lung of civil society group Function 8.
Meanwhile, a protest in support of Amos was also held in Hong Kong yesterday. Fifty people from different civic and political groups gathered outside the commercial building in Admiralty where the Singapore Consulate-General is located. They demanded the immediate release of Yee.
They also burnt effigies and masks of founding Prime Minister Lee Kuan Yew and Prime Minister Lee Hsien Loong.
Among the speakers at the protest was Singapore opposition politician Goh Meng Seng, who lives in Hong Kong and wrote about the event on his Facebook page.
Mr Goh left the National Solidarity Party, of which he was secretary-general, in 2011, and applied to register a new political party, the People's Power Party, in May this year.
"I don't like Amos because he's rude in the Singapore context. But I have to defend his rights," Mr Goh was quoted as saying in the South China Morning Post.
He also denounced Yee's treatment as "horrible", adding: "If the Government can do such thing to a 16-year-old kid, they can do it to an adult too.
"Anyone in the opposition camp should be prepared for that."
Yesterday's public protest was the second in the territory in support of Yee.
The Hong Kong University (HKU) Students' Union organised one on June 30 which saw about 50 to 60 students from universities such as HKU and the Chinese University of Hong Kong gather outside the Singapore consulate.