Gate-all-around integrated circuit structures having a removed substrate, and methods of fabricating gate-all-around integrated circuit structures having a removed substrate, are described. For example, an integrated circuit structure includes a vertical arrangement of horizontal nanowires. A gate stack surrounds a channel region of the vertical arrangement of horizontal nanowires. A pair of non-discrete epitaxial source or drain structures is at first and second ends of the vertical arrangement of horizontal nanowires. A pair of dielectric spacers is between the pair of non-discrete epitaxial source or drain structures and the gate stack. The pair of dielectric spacers and the gate stack have co-planar top surfaces. The pair of dielectric spacers, the gate stack and the pair of non-discrete epitaxial source or drain structures have co-planar bottom surfaces.