It has three Pratt & Whitney JT8D engines. One engine is at the back, and the other two are on the sides of the plane. The 727 is the only plane made by Boeing which has three engines. The Boeing 727 was made after the Boeing 707.

The Boeing 727 is a "trijet," meaning it is powered by three engines. This distinctive configuration was a hallmark of the aircraft, which was designed in the early 1960s to bridge the gap between short-haul twin-engine planes and long-haul four-engine jets. Two of the engines are mounted on pylons at the rear of the fuselage, one on each side. The third engine is located in the center of the tail, with its air intake at the base of the vertical stabilizer, fed through an "S-duct" that curves down into the fuselage. The 727 used the Pratt & Whitney JT8D low-bypass turbofan, which was powerful and reliable but also famously loud, eventually requiring "hush kits" to meet modern noise regulations. The three-engine design was specifically requested by airlines like Eastern Air Lines to allow for safe overwater flights to the Caribbean, as twin-engine planes were restricted by early FAA regulations (before the advent of ETOPS). This setup gave the 727 excellent short-field performance, allowing it to operate from smaller airports with shorter runways than the four-engine 707.