Walker picked up North Shields' Player of the Season last year and had been an ever-present in the Robins' backline since re-signing for the club in July 2021.
"I'm excited to join the club," he said.
"It all came about unexpectedly and last minute really. Jon McDonald messaged me last week to say that Jon Shaw was moving on and that he needed a defender to replace him.
"It wasn't a straight forward decision as I was fully prepared to start the season at North Shields, but having played in this league last season and also having the chance to challenge for this league this season was too much of a draw and I couldn't turn it down.
"My time at Shields was great. I love all the lads there and I am a bit gutted things turned out the way they did for the players, staff and the club.
"However, as I mentioned, playing in this league and looking to challenge for the title was an important factor in joining Dunston.
Walker, who predominantly plays as a centre-half but can also operate anywhere across the backline, becomes Jon McDonald's sixth summer signing.
"I've worked with Jack before. He's a consistent performer, versatile and reliable," McDonald said.
"I know he will fit in with the group easily and I believe that he's another excellent addition to our squad."
Photo credit: Beauty Time Photography