The enlarged, three-engined version of the Falcon 20 is called the Falcon 50. The third engine is placed in the rear fuselage, with an S-shaped duct leading to the air intake on top of the fuselage, in front of the tail. Unlike the Falcon 20 the horizontal stabilisers have anhedral instead of dihedral. The Falcon 50 has the same large oval cabin windows as the Falcon 20, in contrast to the Falcon 900s and 7X/8X with smaller windows.

The base variant is called just Falcon 50. It is powered by Honeywell TFE731-3-1C engines, of which the exhaust pipe is visible in the rear of the nacelle, when viewed (slightly) from behind. The Falcon 50 has an optional auxiliary power unit (APU). The exhaust of this is visible on the right side of the fuselage, behind the righthand engine.

In Italian military service the Falcon 50 is designated as VC-50A.

After the introduction of the Falcon 50EX, see below, not only the Falcon 50-40 was offered as a conversion programme for early-model Falcon 50s, but also the Falcon 50-4. This features TFE731-4 engines in the place of the original TFE731-3s. These have no clearly visible exhaust pipe in the nacelle, but just like the Falcon 50EX and Falcon 50-40.

The Falcon 50EX is a modernized Falcon 50, amongst others with new engines and avionics. These fit in the same nacelles, but have no visible exhaust pipe. Furthermore, an APU installed as standard equipment and there are changes to the rudder control system.

Newly-built aircraft are known as Falcon 50EX. At Honeywell, you can have your old Falcon 50 equipped with the engines and avionics of the Falcon 50EX, and then you get a Falcon 50-40 (with 40 coming from the TFE731-40 engines). You cannot recognise it from the Falcon 50EX and 50-4 from the outside.

A special purpose version of the Falcon 50 is the Falcon 50 SURMAR, sometimes referred to as Falcon 50M or Falcon 50MS. It is a maritime patrol version of the French navy, with large observations windows in place of the first cabin window, on both sides.