Due out in February, priced £1,399, the XF 100-400mm f/4.5-5.6 R LM OIS WR is designed to deliver the 35mm equivalent of a 152-609mm lens.
The 21-element-in-14-groups lens boasts five ED lenses and a Super ED lens to help cut chromatic aberration.
Weighing just under 1.4kg, the lens is built to deliver image stabilisation equivalent to five stops and resist water, dust and temperatures down to -10° C.
The lens features 13 water and dust-resistant seals.
Fuji has added a fluorine coating to the front lens element to help repel water and dirt.
A kit that includes a 1.4x teleconverter will cost £1,499.