The aircraft has a top speed of Mach 1.8 at 40,000 ft. The engine air inlets of the Hornet, like that of the F-16, are of a simpler fixed design, while those of the F-4, F-14, and F-15 have variable geometry or variable intake ramp air inlets.

The maximum speed of the F/A-18 Hornet and the newer F/A-18E/F Super Hornet is approximately Mach 1.8, which is about 1,190 mph (1,915 km/h) at high altitude. Specifically, the latest Block III Super Hornet is rated for a top speed of Mach 1.6 in a typical combat configuration. While this makes the F-18 extremely fast, it is not the fastest jet in the US inventory; for comparison, the F-15 Eagle can exceed Mach 2.5. The F-18 was designed more as a versatile, carrier-based "multi-role" fighter rather than a pure interceptor, prioritizing maneuverability, advanced electronics, and the ability to carry a wide variety of weapons over extreme top-end speed. The aircraft achieves these speeds using two General Electric F414-GE-400 turbofan engines, which produce a combined thrust of 44,000 pounds with afterburners. In practical combat scenarios, pilots rarely fly at these maximum speeds because doing so consumes fuel at an astronomical rate, significantly reducing the aircraft's mission range. Instead, most supersonic flight is done in short bursts or during specific "dash" maneuvers to intercept a target or evade a threat before returning to more fuel-efficient subsonic cruising speeds.