Poly(sulfur‐co‐1,3‐diisopropenyl benzene) copolymers with varying compositions are synthesized from elemental sulfur and 1,3‐diisopropenyl benzene by melt polymerization. The resulting polymers are spin‐coated onto silicon wafers, and their thin‐film properties (thickness, surface composition, hydrophobicity, swellability, roughness, and morphology) are studied. The surface composition of the polymer films (determined by X‐ray photoelectron spectroscopy) indicates that the carbon‐containing repeat units of the polymer segregate to the air–polymer interface, so that the resulting surfaces are hydrophobic. This is in line with results from surface plasmon resonance spectroscopy measurements, which indicate that the materials are protein‐adhesive. Atomic force microscopy reveals that all materials are quite rough and show signs of microphase separation. Antimicrobial assays reveal that the materials are moderately active against Escherichia coli.