The 2 1/2 minute-long, amateur 8mm film was shot in early 1959 -- three years before Monroe's death from a drug overdose -- by a young naval officer she met while visiting his base in San Diego. The actress later invited him to visit the "Hot" set at the nearby Hotel Del Coronado.
The footage he shot was discovered by his daughter after his death.
"Marilyn Monroe memorabilia is always in demand, but rarely do we get one-off material like this," auctioneer Charles Leski said in a statement. "It is also extremely rare for such important archival footage to be auctioned outside of the U.S. before its domestic release, and for that we are extremely proud."
Still in its original Kodak box, the film includes candid images of Monroe, "Hot" co-star Tony Curtis and the film's director, Billy Wilder.
The lot includes CD and DVD copies, along with the original film, and will be sold by Leski Auctions in Melbourne Sept. 25.
The purchaser also acquires full commercial rights worldwide, the auctioneer said.