The Olympus Pen S is a half-frame 35mm viewfinder camera from the Pen series Olympus introduced at the end of the 1950s. It was a compact, fixed-lens model aimed at photographers who wanted to double the number of frames per roll of 135 film.

At recent UK auction, hammer prices for the Pen S have been modest, with the two recorded sales landing at £40 and £50 — a tight £40–£50 range and a median around £45. As of today in 2026 the model sells for low double-digit figures at saleroom level, and clean, working examples with an intact selenium-free shutter tend to sit at the upper end of that band.