The versatile 26-year-old joins following a spell in his Northern Ireland with top-flight side Portadown.
Doherty, a left-footed player who has played at left midfield, left-back and central midfield, came through the ranks at Watford after moving to England at the age of 16 and made an appearance for the Hornets in the Championship before spells with Leyton Orient, Altrincham and Northern Irish outfit Ards.
A three-and-a-half spell with Crawley Town between September 2017 and January 2021 is where Doherty picked up the bulk of his senior experience as he represented the club almost 100 times in League Two, he also has stints at Colchester United and Barnet to his name.
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Capped by Northern Ireland up to Under-21 level, the 26-year-old has now agreed to move to the North East.
Doherty said: “I’m over the moon to have signed for South Shields and can’t wait to get started.
“After meeting with the manager and the other staff, the ambition of the club was clear and I wanted to be a part of it. They came so close to promotion last season and our job is to get over the line this time, because this is a club that wants to go places.
“I couldn’t say no when I heard about the plans for the future and had a look at the facilities, which shocked me in a very good way. I’m really excited about what lies ahead.”
South Shields manager Kevin Phillips added: “We’re absolutely delighted that Josh has decided to join us.
“He is very excited about the project we’ve presented to him for not just this season, but the years ahead, and it’s brilliant to have him as part of the squad.
“Josh brings great attributes to the squad. He has an unbelievable left foot, brings good energy and has a fantastic delivery.
“He has a terrific attitude and can also play in various positions, which is a huge bonus and provides added competition to areas of the pitch we felt it was needed.
“This is an important addition for us and I firmly believe our fans will be very excited when they see Josh play.”