On June 19, Wilson was claimed off waivers by the Seattle Mariners. While with the Seattle Mariners, he was affectionately nicknamed "The Paperboy" by Ken Griffey Jr. With the Mariners in '09 he hit .250 with eight doubles, one triple, three home runs and 10 RBIs in 45 games giving him a combined average of .219 with 42 hits in 72 games between Arizona, San Diego and Seattle.
Wilson was acquired by the Seattle Mariners on June 19. The team's players nicknamed him "The Paperboy" during his time there. In 2009, while playing for the Mariners, he achieved a batting average of .250 with eight doubles, one triple, and three home runs in 45 games, resulting in an overall average of .219 across Arizona, San Diego, and Seattle.