The match against Billy Davies side will be played in Vila Real de Santo Antonio in the Algarve on Saturday, July 6, with an 8pm kick-off.
Easter Road boss Pat Fenlon said: "We are delighted that Nottingham Forest have agreed to this fixture. Forest are a quality team and this will be an excellent test for the squad as we build towards our Europa League qualifiers."
Hibs will play a Gibralter FA XI at Victoria Park on the British territory on Wednesday, July 3, before facing Forest three days later.
Their only other pre-season friendly is against Raith Rovers at Stark's Park on Friday, July 12.
Fenlon will learn the name of Hibs' Europa League opponents on Monday when the draw for the second qualifying round takes place in Nyon.
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