The 17 include former Air Forces Commander Akın Öztürk, Gendarmerie Brigadier General Ali Osman Gürcan, and General Mehmet Dişli, who was accused of attempting to convince then Commander in Chief Hulusi Akar to join the coup attempt.
Former Colonel Ali Yazıcı, who served as an aide to Erdoğan up until the coup, was also sentenced to life in prison.
Interior Minister Süleyman Soylu said in March that that 511,000 people had been detained and 30,821 charged in operations against the FETÖ since 2016.
More than 130,000 public servants were also summarily dismissed from their jobs during two years of emergency rule declared following the failed coup.