Hydrogen bonds are great noncovalent interactions for guiding self‐assembly processes in organic semiconductors. Their presence in molecular structures allows to modify their aggregation state by changing the solvent, concentration and temperature. Here we show that just by functionalizing simple thiophene‐capped diketopyrrolopyrrole derivatives with semicarbazone units, the optical and self‐assembly properties can be tuned while controlling the formation of hydrogen bonding. The appearance of J‐type aggregates upon hydrogen‐bond formation made possible to vary the energy band gaps and supramolecular structures formed in solution and on thin films.