Ethnic Albanians make up around a quarter of Macedonia's two million people, and Albanian has until now been an official language only in areas where the minority makes up certain numbers.
Macedonian is the primary language used across the predominantly Slavic country.
Now ethnic Albanians will be able to request nationwide that their language be used in their administrative, health, judicial, police and other such official matters. In parliament, it can be used by their elected representatives.
The justice ministry said citizens can request "within all institutions" the use of a language that is "used by 20 percent of Macedonian citizens". Only Macedonian and Albanian meet this definition.
The adoption of the law was a demand of Macedonia's ethnic Albanian parties before they agreed to join a ruling coalition with the Social Democrats last year.
The deal ousted the nationalist rightwing VMRO-DPMNE party, in power since 2006.
The VMRO-DPMNE has said the new law risks breaking up the fragile ex-Yugoslav republic.
"It is Macedonia that will benefit from this law, ethnic relations will relax," said MP Artan Grubi from the Democratic Union for Integration, the largest Albanian party.
In 2001 ethnic Albanian rebels waged an insurgency against Macedonian authorities, which left more than 100 people dead and ended with an agreement providing greater rights for the minority.
But many Albanians still consider themselves victims of discrimination, especially in terms of economic investment.