Tyson wrote the romantic notes to then-girlfriend Charlene Friend from behind bars in 1993, while he was serving time in Indiana following his rape conviction.
The letters will be among the highlight items at the Julien's Auctions Music Icons and Sports Legends sale on 23 and 24 June (12).
Also going under the hammer: the Princesse Tam & Tim outfit Amy Winehouse wore in her Rehab video, antique furnishings from Meat Loaf's home, Keith Richards' ripped 'Hell' T-shirt from the Rolling Stones' 1981 American Tour, and jewellery from Elvis Presley's collection, including an E.P. pendant given to him onstage in Las Vegas in 1974 and a ruby and diamond gold ring The King gave his Uncle Vester.
The ring is expected to fetch up to $20,000 (£12,500).