From today, the Policing Authority has responsibility for running competitions for appointments to senior garda ranks.
They include assistant garda commissioner, chief superintendent, and superintendent.
Tánaiste and Minister for Justice Frances Fitzgerald said the establishment of the Policing Authority represented one of the most significant reforms to the justice sector in recent years.
She said the transfer of the appointment function in relation to the senior ranks was a particularly important demonstration of this reform.
Ms Fitzgerald wished the authority every success in what she said was an "onerous responsibility".
The Policing Authority was established as an independent body at the beginning of last year to oversee the performance of An Garda Síochána in relation to policing services in the country.
Inspectors and superintendents in both An Garda Síochána and the Police Service of Northern Ireland (PSNI) are eligible to apply for appointment to the assistant commissioner and chief superintendent ranks.