Seacrest's New Chick -- Scores Huge Modeling Contract ... Thanks to Ryan Hook Up

Ryan Seacrest still has the Midas touch ... 'cause his sexy new rebound chick just inked a deal with one of the biggest modeling agencies on the planet.

TMZ has learned Shayna Taylor -- a.k.a. Ryan's hot new blonde -- signed a 2-year deal with Wilhelmina Models yesterday.

We're told Shayna's Instagram BLEW UP with new followers following the Thanksgiving holiday she spent with Ryan and his family in Argentina ... and the modeling agency took notice.

Plus, she's really hot.

A rep for Wilhemina tells us they believe Shayna has "huge potential in the fitness and lifestyle world."

Shayna is publicly saying she and Ryan are just friends -- but, c'mon ... what kind of friends travel around the world together with Seacrest's parents.