According to the indictment, released on Monday, Ahmed stands accused of pledging allegiance one or both of the terror groups Islamic State (IS) and Jabath Al Nusra.
He then obtained weapons and fought in Syria for nearly five months until he returned to Norway with a bullet wound to the leg.
The man has been charged under article 147a and article 147 d of Norway's criminal code, the second article of which came into force in June 2013.
Also on Monday, the Police Security Service said that it had arrested a 49 year old man, charging him with recruiting others to terror groups (article 147c).
According to Norway's VG newspaper, the man was arrested at the offices of Aker Solutions, one of Norway's biggest blue chip companies, where he worked.
"We have today suspended an employee after our inspection revealed that he had violated of the company's internal guidelines" the company told the newspaper. "The police have been informed about the case and decided to arrest the person in our offices today at Fornebu."
According to the indictment, Ahmed had maintained contact with Isis members since his return and pledged to raise money and collect clothes, shoes and other equipment to send to those fighting in Syria.
The indictment claims Ahmed travelled to Syria intending “to seriously intimidate the Syrian population and force the Syrian government to hand over power”.
John Elden, the Norwegian lawyer defending Ahmed, said that his client rejected the charges.
“He denies any guilt and has not supported or planned terrorist acts in any way. He believes he worked as a humanitarian against oppression.”