Thiam has previously played for teams including Mossley, Stockport Town, FC United of Manchester and Fleetwood Town in League One.
He can also play at right wing back and has already shown his capability to score.
“Making my debut for Fleetwood in League One away at Sunderland in front of 29,000 people was the highlight of my career so far,” said Thiam, who added that he was on board to help Avro fly this season.
“I’ve enjoyed it since I’ve come here and the squad has helped me get back fit.
“It is good to be able to say that I am enjoying my footy again.
“I can’t wait to start the season with the lads and hopefully have a successful campaign under the new managers.”
“Chiekh really impressed me when he joined us last season from Rylands,” said Avro's first team match day secretary Mark Hutton.
“He came into the team at the back end of the campaign and made a big contribution with some great performances.
“We are looking forward to seeing him over a full season.”
Meanwhile, Avro have been drawn at home against Bury FC in the FA Cup preliminary round.
The tie will take place on Saturday, August 17 (kick-off 3pm).
