A new and distinct cultivar of Chrysanthemum plant named `Yorockport`, characterized by its uniform and somewhat outwardly spreading plant habit; strong and freely branching growth habit; dark green-colored foliage; uniform flowering response and habit; can be grown as a spray-type or without bud removal; early flowering habit; daisy-type inflorescences with elongated oblong-shaped ray florets; intense red purple-colored ray florets; and excellent postproduction longevity with plants maintaining good substance and color for about four weeks in an interior environment.