A method of assembling customized footwear on-site and a customized on-site footwear system. The method of assembling customized footwear on-site includes the steps of displaying a plurality of shoe bases; displaying a plurality of heels; displaying a plurality of lower fore-foot straps; receiving from an on-site customer a selection of one of a plurality of shoe bases; and assembling the selected heel, shoe base, and lower fore-foot strap into the customized footwear on-site. The customized on-site footwear system includes a chosen-on-site shoe base, a chosen-on-site heel, and a chosen-on-site lower fore-foot strap.