With 97.7% of the votes counted, the electoral board pronounced Mr Erdogan as the winner with an "absolute majority" of valid votes.
By securing more than 50% of the vote, the 64-year-old who has led Turkey for the past 15 years avoided a presidential runoff, which would have been held on July 8th.
His closest challenger, Muharrem Ince, received 30.8% and the only female candidate, Meral Aksener, 7.4%.
Speaking on national television, Mr Erdogan said: "The nation has entrusted to me the responsibility of the presidency and the executive duty."
Erdogan’s victory paves the way for another five-year term. Under the new constitution, he could serve a further term from 2023, taking him to 2028./.