They chimed 49 times in the Florida city on Monday, once for each of the victims who died in an attack on the city's Pulse nightclub
Speaking to survivors and victims' families during a private service to mark the occasion, the Florida city's mayor Buddy Dyer said: "I realise that gathering here in this place, at this hour, is beyond difficult.
"But I also know that the strength you've shown over the past year will carry you through today and in the future."
Omar Mateen, the man behind the attack on 12th June 2016, had pledged allegiance to the Islamic State group. He was later killed during a three hour standoff with police.
Named of each of victims were read out outside the gay nightclub, while hundreds of people left flowers, drawings and cards at a nearby memorial. Governor Rick Scott ordered that US flags in the state be flown at half-mast.
Noor Salman, the wife of Omar Mateen, faces charges in a federal court of aiding and abetting and obstruction. She has pleaded not guilty to being involved in the shooting.
Monday's services marked the culmination of several days of days marking the attack. The owner of the Pulse nightclub, Barbara Poma, is said to be planning to erect a memorial on the site.