SS Pere Marquette 18 was a steel-hulled Great Lakes train ferry that served on Lake Michigan (primarily between the four ports of Ludington, Michigan and Kewaunee, Manitowoc and Milwaukee, Wisconsin) from her construction in 1902 to her sinking in 1910.

On September 9, 1910 while bound from Ludington for Milwaukee with 62 passengers and crew and 29 rail cars filled with general merchandise and coal, Pere Marquette 18 began taking on massive amounts of water. The pumps were turned on, but all attempts to save her were futile, and she sank off the coast of Sheboygan, Wisconsin. Her fleetmate, Pere Marquette 17 was nearby and managed to save 35 of her passengers and crew. Twenty-seven people on board Pere Marquette 18 were killed, while Pere Marquette 17 lost two of her own crew during the rescue. As none of her officers survived to recount what happened, the true cause of Pere Marquette 18's flooding remains a mystery.

The wreck of Pere Marquette 18 was discovered in July 2020 in about 500 feet (150 m) of water about 25 miles (40 km) east of Sheboygan by a wreck hunting team from Minnesota.