The 2006 Australian Open runner-up, who is now ranked 132, has only played in one other ATP Challenger event since 2009, retiring in the first round against Igor Sijsling in Dallas last year.
Cypriot star Baghdatis could again meet Sijsling at the Nottingham Tennis Centre, with the World No.55 the highest ranked player to enter the Trophy.
As well as his run to the Australian Open final, former World No.8 Baghdatis has had success on grass in the past, beating Wimbledon champions Andy Murray and Lleyton Hewitt in reaching the semi-finals in 2006.
Paul Hutchins, Aegon Trophy tournament director, said: “Marcos is a hugely popular character and we are delighted that he is in Nottingham to start his grass court campaign.”
“From here Marcos will go on to the Aegon Championships at the Queen’s Club where he has a wild card, so he will have plenty of time to sharpen those skills ahead of Wimbledon.
“I would have liked to give him a wild card into the tournament, but all those spots have gone to British players, James Ward, Dan Cox, Daniel Smethurst and Kyle Edmund.”
British No. 2 Dan Evans is among nine top 100 players to compete, with defending champion Matthew Ebden and last year’s beaten finalist Benjamin Becker returning.
Australian Marinko Matosevic, who was beaten by Andy Murray in the second round of the French Open on Thursday, is the second highest ranked player in the main draw
Nottingham Post