The 32-year-old striker, who can also operate as a winger, is the Seasiders' second arrival of the summer and follows the permanent addition of Aaron Haswell at The Towbar Express Stadium @ The Turnbull Ground, writes Liam Ryder.
Franks adds great experience to Lee Bullock and Nathan Haslam's options having made just shy of 250 professional appearances.
Speaking after completing his move to Town, Franks said: "I know a few players who have played for Whitby in the past and they've said nothing but good things about the club.
"I've watched a few Whitby games before in the past so I understand what the club's about and it's a very passionate town as well so it's something that I'm looking forward to being part of."
Born in Stockton, Franks began his career at nearby Middlesbrough.
After coming through the club's academy system, he made 28 appearances in all competitions for Boro and spent time with Oxford United and Yeovil Town on loan.
Franks joined Hartlepool United in 2012 and made 149 appearances for them over two spells before heading out to Sweden following a brief spell with Wrexham.
Franks moved to his hometown club Stockton Town in 2020 where he made 24 appearances.