There were over 1,000 cases of children going missing from state care between 2018 and 2020.
They range from people aged 11 to 17.
These new figures, released under the Freedom of Information Act, relate to children going missing from state residential care.
That includes boys and girls in special care, along with voluntary, private, and Tusla care.
There were 319 cases of children going missing last year, with 366 in 2019 and 330 in 2018.
They range from people aged 11 to 17.
Almost half involved children going missing from private residential care centres.
"Children who are placed in residential care have high levels of need and often come from chaotic home environments," says Suzanne Connolly who is CEO of children's charity Barnardos.
"There are very few household rules and boundaries and therefore they can find it very hard to settle into the structure of residential care life.
"They then abscond and engage in quite risky behaviour which puts themselves and others at risk."
Tusla says the majority of the cases involve children who are missing less than 24 hours.
The agency says the gardai must be notified by care staff that a child's missing from their placement for longer than expected - and the carers can't find them.