This paper presents the design of a modular full-body assistive exoskeleton (FB-AXO) for older adults which was developed with funding under the AAL funded AXO-SUIT project. Processes used to formulate a prioritized set of functional and design requirements via close-end-user involvement are outlined and used in realizing the exoskeleton. Design of the resulting mechanics and electronics details for the lower and upper-body subsystems (LB-AXO and (UB-AXO)) are described. Innovative designs of shoulder and spine mechanisms are presented. TheFB-AXO system comprises 27 degrees of freedom, of which 17 are passive and 10 active. The exoskeleton assists full-body motions such as walking, standing, bending, as well as performing lifting and carrying tasks to assist older users performing tasks of daily living.