Williams had been on trial with the Tynesiders during pre-season and has signed a short term deal until January 2022.
The 28-year-old midfielder was released by Hartlepool United in the summer after an injury hit three seasons at Victoria Park in which he made just one league start.
But he will remain in the north east in full-time football at Gateshead, who are managed by former Newcastle United defender Mike Williamson.
After signing, Williams told the Gateshead website: “It’s massive, it’s close to the season now and I’m just happy to get it over the line and get focused on playing games and hopefully winning games.
"I feel great, I spent pretty much the full season last season fit which was massive for me but what I needed to really kick on. Now I’m ready to play games.”