AU commission chairperson Nkosazana Dlamini Zuma hailed its creation as the moment when Africa “got [its] own digital identity”.
The AU says the .africa domain name will “bring the continent together as an internet community”.
Addresses can now reflect a company’s interest in the whole of Africa.
For example, a mobile phone company could create mobile.africa to show its Africa-wide presence, or a travel company could set up travel.africa.
Icann, the body that establishes these addresses known as generic Top-Level Domains, approved the move, after lobbying by the AU.
The campaign was spearheaded by a South African company ZA Central Registry (ZACR), which will now be responsible for registering .africa names.
ZACR’s boss Lucky Masilela said that .africa addresses could cost as little as $18 (£15), AFP news agency quotes him as saying, and registration will start in July.
Other domain names recently created by Icann, include .fun, .phone and .hair.