Bob Bowman, who guided Phelps to a record 18 golds and 22 medals overall at the Olympics, will help select swimmers and advise the Turkish Swimming Federation on strategies to develop competitors, Turkey's Youth and Sports Ministry said on Tuesday.
The appointment is part of a Turkish policy to develop athletes in swimming and other major Olympic events.
It came after Turkish mobile phone company Turkcell agreed to sponsor swimming and athletics.
Bowman's first task will be to select swimmers with potential among some 200 000 youths, a ministry official said.
No Turkish swimmer has won an Olympic medal.