Sweeping relaxations announced by the Government on Friday evening came into effect at 6am on Saturday.
The move will see an 8pm curfew on the hospitality sector lifted with pubs and restaurants able to trade restriction free.
Covid certification passes will no longer be required to gain entry to hospitality, entertainment and leisure outlets.
Live events and sporting events can return to full capacity audiences and guidance advising limits on household visits has been removed.
Workers across Ireland will return to offices on a staggered basis from Monday.
Only a small number of restrictions remain in place, including the continued requirement to wear masks in settings such as in shops, schools and on public transport; self-isolation rules; and the use of Covid passes for international travel.
In a televised address on Friday, premier Micheal Martin told the nation it was “time to be ourselves again”.
The relaxations have come swifter than many expected.
They were made possible after the health experts in Ireland’s National Public Health Emergency Team (Nphet) advised Government that there was no longer a public health rationale for keeping the measures in place, with the country having weathered the Omicron storm.
Protective measures will remain in place in primary and secondary schools until at least the end of February. They will be reviewed at that point, by which time all children aged five to 11 will have had the opportunity to be vaccinated.
Taoiseach Mr Martin warned that the coronavirus pandemic is not over.
But he added: “Spring is coming. I don’t know if I’ve ever looked forward to one as much as I’m looking forward to this one.
“Humans are social beings and we Irish are more social than most.
“As we look forward to this spring, we need to see each other again. We need to see each other smile. We need to sing again.
“As we navigate this new phase of Covid, it is time to be ourselves again.”