System and method embodiments are provided for messaging-based System-on-a-chip (SoC) power gating. The embodiments enable fine granularity SoC power gating without introducing significant latency and substantially maximizes SoC power reduction. In an embodiment, a method in a first SoC resource for messaging-based power gating includes receiving at the first SoC resource a wakeup notification message (WNM) from a second SoC resource, wherein the WNM comprises a time at which a result message from the second SoC resource is expected to arrive at the first SoC resource; determining with the first SoC resource a wake-up time according to the time at which the result message from the second SoC resource is expected to arrive at the first SoC resource; setting a wake-up time timer to expire at the wake-up time; and waking up the first SoC resource when the wake-up time timer expires when the first SoC resource is asleep.