Siti Rafeah Abd Hamid, 44, was working at Frontier Primary School in Jurong West when she committed the offences, which came to light when the school realised it could not pay a CCA vendor due to insufficient funds.
The mother-of-five was jailed for four months on Monday (April 1) after she pleaded guilty to one count of criminal breach of trust involving more than $36,000.
A second similar charge involving $4,800 was taken into consideration during sentencing.
The court heard that Siti joined the school in January 2012.
As part of her job scope between January and November 2017, she was entrusted with monies for various activities such as school trips and CCA activities.
Deputy Public Prosecutor Deborah Lee said: "These monies were collected by teachers from students and handed over to the accused.
"The accused was supposed to record these monies in the school system before handing the monies over to the operation manager. The operation manager would then deposit the monies into the school's bank account."
In July last year, the school realised that it could not pay a CCA vendor, and internal investigations later revealed that Siti did not hand over more than $36,000 to the operation manager.
The DPP added: "The accused admitted that she dishonestly misappropriated the said sum by using them for her own expenses. The accused also did not record the said sum in the school system to avoid detection."
The school's vice-principal alerted the police on July 27 last year.
Siti has since made full restitution, the court heard.
The Ministry of Education (MOE) said she is currently on no-pay leave and it will commence disciplinary process accordingly.
The MOE added that it takes a serious view of staff misconduct and will not hesitate to take disciplinary action against those who fail to adhere to its standards of conduct and discipline, including dismissal from service.
It also said it has been taking steps to tighten the accountability of billing and collections through an MOE billing system for schools.
In asking for a four-month jail term, DPP Lee told District Judge Toh Yung Cheong that Siti had committed the offences for over a year and that the amount involved was significant.
Defence lawyer T. M. Sinnadurai said this was Siti's first brush with the law.
The lawyer also said she had fully cooperated with the authorities.
For criminal breach of trust, she could have been jailed for up to seven years and fined.