Magnesium alloys are one of the lightest commercial metals, and applications of wrought magnesium alloys may lead to a substantial weight reduction of transportation vehicles. However, applications of wrought magnesium alloys are limited due to processing costs. This chapter discusses the requirements to broaden their applications through a brief review of existing wrought alloys. Then, a heat treatable wrought magnesium alloy is proposed as a new design concept for the wrought magnesium alloy. As an industrially viable precipitation hardenable alloy, Mg–Ca–Al(–Zn) dilute alloy is developed. A high strength Mg–Al–Ca–Mn alloy extrudable at high speed and a bake-hardenable Mg–Al–Ca–Mn–Zn alloy sheet with excellent room temperature formability and satisfactory strength are demonstrated, indicating the promising potential to develop heat treatable wrought magnesium alloys.