Gate-all-around integrated circuit structures having backside contact self-aligned to epitaxial source or drain region are described. For example, an integrated circuit structure includes a first vertical arrangement of nanowires and a second vertical arrangement of nanowires. A gate stack is over the first and second vertical arrangements of nanowires. First epitaxial source or drain structures are at ends of the first vertical arrangement of nanowires. Second epitaxial source or drain structures are at ends of the second vertical arrangement of nanowires. A conductive structure is vertically beneath and in contact with one of the first epitaxial source or drain structures.