Sugar Loaf is a bluff on the Mississippi River topped by a rock pinnacle, overlooking the city of Winona, Minnesota, United States.

[3] Sugar Loaf's distinctive pinnacle resulted from quarrying the bluff's limestone cap layer through most of the 1880s, which was then used for Winona's sidewalks and stone buildings.

Many miles of this limestone were installed before the turn of the 20th century and met with such success that a city ordinance was passed in late 1890 specifying stone-only for sidewalks.

[5] In its original configuration as a rounded half-dome with a fringe of evergreen on the crown, the bluff was well known to early explorers, traders, tourists, and river boat pilots.

At least three other hills or bluffs bearing the name "Sugar Loaf" are located in or near the Mississippi River Valley in proximity to Winona.