Daniel Alfei has signed a two-year deal with the Glovers to become the club's ninth summer signing.
Having spent time on trial with Town, the 25-year-old has put pen to paper on a deal that will see him remain in Somerset until at least 2019.
The right-back rose through the ranks at Swansea's Academy, earning international call-ups for Wales at Under-17, 19 and 21 level in the process.
Signing a professional contract at the Liberty Stadium in 2011, Alfei was named man of the match on his first-team debut, a 4-0 win over Colchester United in the FA Cup.
The Swansea-born defender made his Premier League debut a week later in January 2011, before making almost 40 EFL appearances during loan spells with Portsmouth, Northampton and Mansfield.
Having featured in Town's last four pre-season fixtures including 90 minutes against Bristol Rovers on Tuesday, Alfei bolsters defensive options ahead of the 2017/18 season.
With the latest addition to his squad confirmed, manager Darren Way told YTFC.net:
"How Daniel has been playing non-league football for Aberystwyth Town is beyond me.
"It's up to him now to take this opportunity and aim for 40 league games this season."
Would you like to sponsor Daniel this season? Please contact Commercial Manager Dave Linney on 01935 847872 or email DLinney@ytfc.net.