A Shamrock Rovers B-team will compete in the SSE Airtricity First Division for the 2020 season.
Shamrock Rovers II - as they've been dubbed - will replace Limerick FC who were denied a licence to compete due to financial issues.
A statement from the FAI said "The National League Executive Committee approved the proposal and the decision was ratified by the FAI Board."
It's not the first time a Rovers B-team have been entered into the First Division.
In the 2014 season, Shamrock Rovers B finished 6th in an 8-team division following the withdrawals of both Salthill Devon and Mervue United.
A fixture list for the 2020 First Division season is yet to be issued.
It's unlikely the decision to parachute Shamrock Rovers II into the First Division will go down well with their fellow participating clubs.
The Irish Times' Emmet Malone reported earlier in the week that all seven First Division clubs were backing a boycott should a Rovers B-team be entered into the league for 2020.
Drogheda United chairman Conor Hoey told Malone the proposal was of benefit to Shamrock Rovers alone, adding, "you have to ask whether Dundalk or St Patrick’s Athletic of Bohemians will be allowed to do it too if they decide they have to follow suit."
However, the Rovers B-team scenario could be a one-season only arrangement.
The Irish Independent's Dan McDonnell has reported that a new Limerick United group will be allowed field teams in the Women's National League and the men's underage set-ups.
It's claimed the plan is to have a Limerick side back in the senior League of Ireland for the 2021 season.