0330 GMT October 24, 2017
The bridge across the Bosphorus strait in Istanbul was the scene of bloody fighting between Erdogan's supporters and renegade soldiers seeking to oust the elected government on the night of July 15, 2016, AFP reported.
It was later renamed by the government as July 15 Martyrs' Bridge.
The dead included Erdogan's campaign manager Erol Olcok and his 16-year-old son Abdullah Tayyip, who were killed when soldiers opened fire on protesters on the bridge which connects Asia and Europe.
Erol Olcok had named his son after Erdogan and his predecessor as president, Abdullah Gul.
The suspects, including 30 officers, appeared in court. All the suspects barring eight are being held under arrest.
They are accused of crimes ranging from murder to attempting to overthrow the parliament and the government, according to the 1,052-page indictment.
If convicted, the suspects each face 37 life sentences, according to the state-run Anadolu Agency.
Many civilians rushed to the bridge on the night of the coup, heeding Erdogan's call to quash the putsch bid, but the renegade soldiers then shot at them.
Thirty-four civilians and seven coup plotters were killed on the Bosphorus Bridge, according to the indictment.
Monday's trial is one of several legal processes seeking to bring to justice those believed to have played a role in the coup bid which left 249 people dead, not including the putschists.
Last week, a court in southwestern Turkey handed life sentences to 40 people convicted of plotting to assassinate Erdogan at an Aegean hotel.
Erdogan has vowed to purge all state institutions to clean the "virus" of US-based political figure Fethullah Gulen whom his government blames for the putsch.
The cleric, who lives in Pennsylvania, has denied any involvement.
Over 50,000 people have been arrested since last July, accused of links to the Gulen movement, while more than 140,000 public sector employees have been sacked or suspended.