Rents in Co Mayo increased by over 7% in the first three months of this year, compared to the same period last year.
The average advertised rent is now €654 per month.
This is considerably lower than the national average rent of €1,261.
Rents nationwide rose by an average of 11.5% in the year to March 2018, according to the latest quarterly rental report by property website Daft.ie.
Rents in Dublin rose by over 12% to an average of €1,875 per month, while in Galway city, rents increased by over 13% to €1,130 per month.
Author of the report, economist Ronan Lyons, says the increasing rents are due to the chronic and worsening lack of supply of rental homes.
He says policy must focus on dramatically increasing the construction of urban apartments over the coming years to meet demand.