The Toyota Sienta is a mini MPV with sliding doors manufactured by Toyota. It was introduced in September 2003, based on the Vitz/Yaris subcompact car, and is available at all Toyota dealerships in Japan. The Sienta is sold in Japan, Hong Kong, Singapore, Indonesia, Taiwan, Laos, and Thailand. As of 2022, it is positioned below the Voxy/Noah and above the Roomy in Toyota's MPV lineup in Japan. In Indonesia and Thailand, it serves as an upmarket alternative to the Avanza and fills the gap between Avanza and the larger Innova.

Mini MPV—an abbreviation for mini multi-purpose vehicle—is a vehicle size class for the smallest size of minivans/MPVs. The mini MPV size class sits below the compact MPV size class and the vehicles are often built on the platforms of B-segment hatchback models. By the European definition, the mini MPV commonly consists of cars with two rows of seats, while in Asia mini MPVs with three rows are common. Sliding doors are sometimes also fitted to mini MPVs. Mini MPVs are also called tall-hatchbacks or small MPVs.