Charlie Flanagan says the Government will soon be able to "formally approve" the selection process
It could be summer 2018 before a new Garda Commissioner is appointed.
Noirín O'Sullivan left the role in September, but a job specification still has not been finished for her replacement.
A new process is in place for appointing a Garda chief, with the Policing Authority to play a significant role in the process.
Justice Minister Charlie Flanagan gave a timeline to the Dáil earlier that means it could be next summer before the Garda top job is filled.
He explained: "I would expect that the Government will be in a position to formally approve the authority to invite the Public Appointments Service to conduct the selection process shortly.
"Once this is done, I would anticipate that it could take up to a period of six months to identify and appoint a successful candidate."
Mrs O'Sullivan's retirement came on the back of calls for her to resign over the controversy involving false Garda breath test data.
Announcing her decision to leave the role, Mrs O'Sullivan expressed frustration "that the core of my job is now about responding to an unending cycle of requests, questions, instructions and public hearings".
Donall O'Cualain is serving as Acting Garda Commissioner, and has previously ruled himself out of applying for the permanent post.
Reporting by Sean Defoe and Stephen McNeice