Every month last year, more than two young people aged 10 to 19 killed themselves.
The year's total of 27 was twice as many as the year before and the highest in 15 years.
The rate also stands in contrast with the overall reported suicide rate in Singapore, which last year was at its lowest since 2012.
Samaritans of Singapore: 1800-221-4444
Singapore Association for Mental Health: 1800-283-7019
Institute of Mental Health's Mobile Crisis Service: 6389-2222
Care Corner Counselling Centre (Mandarin): 1800-353-5800
Troubled young people who reach out to suicide prevention agency Samaritans of Singapore (SOS) cite mental health issues, academic pressure, and relationship problems at home and in school as their greatest source of stress.
The number of suicides in this group has risen even as the group itself is shrinking, declining by 7.1 per cent since 2012, thus underscoring the increasing urgency of identifying and helping children at risk, said experts.
Overall, there were 409 reported suicides in the 2015 financial year, compared with 415 in 2014.
It resulted in a suicide rate of 8.43 per 100,000 population, a sharp drop from 10.27 in 2012.
However, the teenage years can be a difficult time when young people struggle with issues of identity and belonging, said the Samaritans of Singapore. At greater risk are those who have mental health issues and are stressed by home and study environments.
Also, growing up in the digital age could make them particularly susceptible to negative online influences that might steer them into harming themselves or developing suicidal tendencies, said Ms Petrine Lim, principal social worker at Fei Yue Community Services.
"Parents who are increasingly busy nowadays might not spend enough time with their children to be able to pick up their changes in mood," said Ms Lim.
"This results in those who are feeling really depressed going online to try to find out how to deal with depression, where there are a whole spectrum of answers and people who might try to give them an outlet for their pain."
Teenagers who lack healthy outlets to express their pain, such as a supportive family and social network, tend to be at risk of self-harm and suicidal thoughts, said counsellors.
Madam Wendy Goh, 31, a housewife and mother of five children aged from one to 10 years old, said she tried to make time at night to listen to every child.
She said in Mandarin: "I think it's important to spend some alone time with each of them, hear how their day has been and how they feel at the end of it."
In other findings, while men made up two-thirds of overall reported suicides, fewer took their lives last year than the year before. In 2015, 271 men and 138 women committed suicide, compared with 292 men and 123 women in 2014.