A distinct cultivar of Chrysanthemum plant named `Watch`, characterized by its large quilled decorative-type inflorescences that are about 11.2 cm in diameter when grown as a disbud and about 8.8 cm in diameter when grown as a natural spray; attractive bright yellow-colored inflorescences with reddish brown centers; response time about 62 days when grown as a disbud and about 66 to 68 days when grown as a natural spray; dark green foliage; reddish brown-colored stems; and excellent postproduction longevity with inflorescences maintaining good substance and color for about three to four weeks in an interior environment.