A head-mounted device may include a housing structure, a display module mounted in the housing structure, and adjustable support structures coupled to the housing structure. The adjustable support structures may include a first portion that rests against a user's forehead and second and third portions that rest against the user's cheeks or temples. In some arrangements, the adjustable support structures include posts with adjustable lengths, telescoping layers of material, inflatable structures, and/or elastomeric materials that expand and retract to accommodate different face shapes and sizes. In some arrangements, the adjustable support structures include a cable located in a flexible member. When pressure is applied to a forehead portion of the flexible member, the cable pulls the temple portions of the flexible member towards each other. In some arrangements, the adjustable support structures include a movable member that pivots about a pivot axis.