The suicide and self harm charity say calls from people under the age of 18 have increased by more than 40% in the first eight months of the year.
The charity say overall demand has grown by 22% since last year, with 4,620 people of all ages seeking support so far in 2021.
Pieta say uncertainty around the pandemic is causing young people more anxiety in general, while there has also been increased demand for support for body image issues.
The number for Pieta's free 24/7 crisis helpline is 1800 247 247.