Calibre 335 (and the similar Calibre 310) was an automatic watch movement from Patek Philippe.
Patek Philippe has a long history in automatic watch movements, dating to Cal. 350 from the 1950's. Although these early movements were successful, they suffered from issues of durability, power reserve, and accuracy. One reason was their iconoclastic design: Cal. 350 had a peripheral rotor while Cal. 240 had a micro rotor. Patek Philippe, like Audemars Piguet and Vacheron Constantin, had turned to Jaeger-LeCoultre for an automatic movement in the 1970's but wanted one of their own design.
Calibre 335 was introduced in 1980 to replace both the Jaeger-LeCoultre-based PP 28-255 and their earlier Cal. 350 and 1-350 movements. It was designed to modern standards, running at 28,800 A/h, and featured a flat balance spring under the non-Gyromax balance. It did not earn the Geneva Seal, much to the consternation of brand enthusiasts. Cal. 335 proved troublesome in practice, with poor power reserve and less than expected accuracy. It was quickly overhauled and the replacement, Cal. 315 and 330 introduced in 1984.
Cal. 335 was too tall at 3.45 mm to replace the Jaeger-LeCoultre-based Cal. 28-255 in the Nautilus, so the movement was reworked for the 1980 introduction of the mid-sized Nautilus Ref. 3800. This new movement was 3.15 mm high but similar in other respects to Cal. 335.