Designed with a chiseled look, the four-door STS features what Cadillac says is a "faster profile" with "more rake" than the CTS. Cadillac styling touches include a wide airfoil grille with dual horizontal slats, a dihedral-shaped hood and vertically stacked twin-projector headlights. The sides of the STS are devoid of decoration. LED taillamps contain indirect optics to provide a more even lighting pattern.

Body-panel gaps promise close tolerances. Either 17- or 18-inch wheels can be installed.