The Gender Recognition Act has been passed by the Oireachtas.
It means transgender people can be fully recognised in their chosen gender.
They will be able to change the gender on their birth certificate and passport.
It also removes a clause in a previous bill which required a supporting statement from a doctor.
Amnesty International says it welcomes the commitment to remove the requirement that applicants for legal gender recognition dissolve their civil partnerships or divorce, should the current legal challenge to the marriage equality referendum be rejected.