Controller and control method for internal combustion engine

A controller configured to control an internal combustion engine, the internal combustion engine being configured to execute multi-shot injection in which injection of fuel by an amount requested in a single combustion cycle is split into two or more injections with a time of suspension between each of the two or more injections and single-shot injection in which fuel is injected once by the amount requested in the single combustion cycle, and the internal combustion engine being configured to execute a deactivating process that stops supplying fuel to at least one of cylinders and supplies fuel to the remaining cylinders,

• the controller being configured to execute, when terminating the deactivating process to restart supplying fuel to a deactivated cylinder in which supply of fuel is stopped, a retarding process that executes a first fuel injection through the single-shot injection so that a fuel injection start timing is retarded by an amount of time that equals a sum of the time of suspension during the multi-shot injection when injecting fuel by the amount requested in the single combustion cycle.