Irish Sign Language is now officially recognised as a native and independent language.
Earlier this month the bill passed through all stages in the Oireachtas.
President Higgins has now signed the legislation, meaning it has become law.
The Recognition of Irish Sign Language for the Deaf Community Bill will benefit around 50,000 members of the deaf community here.
The language can now be used in the courts when necessary.
The bill introduces statutory targets for the accessibility of television programming.
It also "provides for the regulation of Irish Sign Language interpreters, deaf interpreters and Irish Sign Language teachers and for that purpose to establish the Irish Sign Language Council".
Speaking earlier this month after the Dáil and Seanad passed the bill, Brian Crean from the Irish Deaf Society explained: “It is not going to solve all barriers in Ireland – but hopefully it will reduce them.
“The deaf community itself will be less marginalised. For example, the services on all public service providers must then provide interpretation for the deaf community that wants to access services.”