There was a 17% increase in the number of sex-offenders jailed last year.
According to details released under the Freedom of Information Act, 287 people were sent to prison for these offences in 2018.
This rose to 336 last year, with 329 men and seven women.
Noeline Blackwell, from Dublin Rape Crisis Centre, says there are a number of factors for the increase:
"The number of complaints being made to gardaí are rising quarter-on-quarter for the last two-and-a-half or three years by about 10-15% each quarter," she said.
"As well as that, there has been some additional resourcing of the justice system," she added.
"For instance, the number of specialist units of investigation by the gardaí, that has risen from that has risen from four to 10."