The Boeing XPB (company Model 50) was an American twin-engined biplane long-range patrol flying boat of the 1920s.

The fuselage had a metal lower part, with the upper half made of laminated wooden frames with a wood veneer covering.

Two 800 hp (600 kW) Packard 2A-2500 V12 engines driving four-bladed propellers were mounted in tandem between the wings above the fuselage.

[1] The Boeing Model 50, designated XPB-1 by the US Navy, made its maiden flight in August 1925.

[2] It was intended to use it to lead a pair of Naval Aircraft Factory PN-9s in an attempt to fly to Hawaii on 31 August 1925, but engine trouble led to its participation in the flight being cancelled.