Samaritans volunteers have listened to almost three million calls over the last five years.
110,000 people made contact with the organisation between March 2014 and March 2019 over issues like mental health.
The busiest time was generally 6pm to midnight.
Six major telecom providers have agreed to support the helpline until 2024. Its free phone number is 116 123.
Samaritans Ireland Regional Director Cindy O'Shea says people are calling mostly about loneliness.
"We're finding in this day and age that the majority of calls that we get are about loneliness and isolation," she said.
"We're really glad to be able to be there to answer the phone and to be able to reduce the barrier of no cost."
More than 500,000 calls were answered by Samaritans volunteers last year, with almost 46,000 text replies and 5,300 emails sent.
Samaritans volunteers have answered almost 3 million calls on freephone 116 123 - a huge thank you to every single one of you 💚💚 pic.twitter.com/Qk5wbzkZr7— Samaritans Ireland (@SamaritansIRL) April 1, 2019
Some 4,000 people were given emotional support in a branch or at a festival.
Communications, Climate Action and Environment Minister Richard Bruton said: “I am delighted that all major telecom providers have agreed to continue to support the Samaritans and the vital work that they do.
“This agreement will mean that there will be no cost barrier to anyone who may need to call the Samaritans.”
Additional reporting by Press Association