The move accelerates a trend in China which has seen automakers launch their own ride-hailing services, and ride-hailing firms such as Didi team with automakers to develop purpose-built cars for their services.
The Japanese carmaker said the new joint venture would include Toyota's Chinese partnership with Guangzhou Automobile Group, and would see the companies combining services and technologies.
The collaboration utilized Toyota's connected technologies and next-generation battery electric vehicles, Toyota Executive Vice President Shigeki Tomoyama said.
Toyota, which has said it aims to get half of its global sales from electrified vehicles by 2025, has tapped Chinese battery makers including Contemporary Amperex Technology and BYD to aid it in the shift to to electricity-powered cars.
Didi has also set up ventures with Volkswagen and BAIC's new-energy vehicle unit.
Sources told Reuters in June that Didi was in talks with Nissan Motor and its China partner, Dongfeng Group, to form another fleet-management venture.
Toyota and Didi have previously collaborated on other vehicle projects and services for Didi drivers.