Toledo, who has been credited with the signing of All-Stars Jose Reyes and Nelson Cruz, as well as more than 30 other Major League players, joins the staff of Tim Kissner, the Mariners' new director of international operations.
Toledo has been in Major League Baseball for the past 32 years, working with the Mets from 1981-2006 and then the Rays from 2006-12.
"We are very excited to add Eddy as our director of Dominican operations," said Kissner. "Eddy is a much-respected scout, and his experience, record of signing Major League players and ability to represent the Mariners in a first-class manner make him the perfect individual for this job."
In addition to Reyes and Cruz, Toledo has helped sign Octavio Dotel, Guillermo Mota, Hector Carrasco, Carlos Gomez, Fernando Martinez, Elvin Ramirez, Alex Colome and Brauilo Lara among other Major Leaguers.
"I am very excited to join the Mariners and assist with the organization's very ambitious efforts in the Dominican Republic," said Toledo. "The future of the Mariners internationally is very bright, and I look forward to working with Tim Kissner, Jack Zduriencik and Joe McIlvaine to provide championship-caliber players to the Major League roster."