A new and unique hybrid cultivar of Phlox plant named Phlox ‘;Cover Girl’; of tall, multi-stemmed, upright habit. Foliage is thick, with exceptional powdery mildew resistance on stiff stems. Lavender-purple are produced on large heads of branched peduncles and nearly cover the top of the plant beginning mid-July and continuing and reblooming for about seven weeks through late summer. ‘;Cover Girl’; is especially suitable as a potted plant, for the garden, for attracting hummingbirds and butterflies, and for cut flower arrangements.