The ban was imposed in March after a recording of a high-level security meeting discussing war plans against neighbouring Syria appeared on the site.
The government had also blocked access to social-media website Twitter on March 20, a week earlier than the YouTube ban.
The Twitter ban was imposed following the anonymous posting of a series of audio recordings which suggested corruption inside the Turkish government, but it was lifted two weeks later.
Recent domestic uprisings in the country have relied on social media and prime minister Recep Tayyip Erdogan has drawn criticism from all over the world for employing authoritarian censorship tactics.