Seventeen-year-old Amos Yee pleaded guilty to the charges and has been ordered to pay around £1,130 for failing to turn up at a police station despite being given notices.
Channel News Asia reported that the judge said the teenager is "not lacking in mental capacity," and that he "deliberately elected to do harm by using offensive and insulting words" to hurt the feelings of Christians and Muslims in the country.
Judge Ong Hian Sun also told him that Yee's conduct could not be tolerated because it undermined religious harmony.
The judge went on to say that he hoped the punishment would act as a deterrent.
The teen was also jailed for four weeks in 2015 after being convicted of the same offence, he eventually spent 50 days in prison after breaching the terms of his bail.
Yee represented himself in court.
The maximum sentence for intending to wound religious feelings in Singapore is three years in prison as well as a fine for each charge or both.
Got my sentence for 'intending to wound religious feelings': 38 days of prison. Going in on the 13th of October
— Amos Yee Kuan Yew (@amosyee) September 29, 2016