The long-term deal means the Italy-based team will be using the same units and gearboxes as champions Red Bull.
Formula One's engine rules are changing next year with the introduction of a new 1.6 litre V6 turbocharged engine with energy recovery systems instead of the current V8.
Red Bull team boss Christian Horner said the Toro Rosso deal made "perfect sense" and would "enable synergies between Red Bull and Renault to continue to grow".
Red Bull would remain the development partner for the new V6 turbo power unit, Renault said.
- Toro Rosso
- Christian Horner