Two-step redox switching in enantiopure helquat system [P-1]2+ → [P-1]●+ → [P-1]0 is demonstrated. The viologen-type electroactive unit embedded directly in the helical scaffold of 1 is responsible for the prominent chiroptical switching at 264 nm. This process is associated with a marked Cotton effect sign-reversal ramping between Δε = +35 M-1 cm-1 for [P-1]2+ and Δε = -100 M-1 cm-1 for [P-1]0. This helically chiral system features the most intense chiroptical switch response documented in the field of helicenoids.