In the address, Recep Tayyip Erdogan vowed to "rip the heads off" of terror groups and of the coup-plotters who tried to end his more than a decade-long rule.
Mr Erdogan joined the large, flag-waving crowd who took part in a national unity march in Istanbul, converging at the iconic July 15 Martyrs' Bridge to remember 250 people who died on July 15 2016 trying to resist the coup.
Accompanied by his family and the families of the deceased, he inaugurated a hollow, globe-shaped monument featuring the names of the victims near the foot of the bridge.
"The July 15 coup attempt is not the first attack against our country, and it won't be the last," he said, referring to a series of terror attacks that also hit the country. "For that reason, we'll first cut the heads off of these traitors."
The bridge was the scene of clashes between civilians and soldiers in tanks. At least 30 people died there and more than 2,000 were injured across Turkey in the struggle. Thirty-five coup plotters were also killed.
Photographs of the 250 "martyrs" were displayed on monitors and their names announced. Mr Erdogan praised their bravery saying they were armed only with Turkish flags and "their faith" while resisting coup-plotters in their tanks.
Mr Erdogan was later due to return to Ankara to address parliament at the exact moment it was bombed a year ago. He is also scheduled to inaugurate another monument honouring the dead.
Turkey blames US-based cleric Fethullah Gulen for orchestrating the coup and infiltrating state institutions. Mr Gulen denies the allegations.
In the aftermath of the coup attempt, Turkey declared a state of emergency that has been in place ever since, which has allowed the government to rule by decree and to dismiss tens of thousands of people from their jobs. More than 50,000 people have also been arrested for alleged links to Mr Gulen and other groups.
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