Mare Vaporum /væˈpɔːrəm/ (Latin vapōrum, the "sea of vapors") is a lunar mare located between the southwest rim of Mare Serenitatis and the southeast rim of Mare Imbrium. It was named by Giovanni Battista Riccioli in 1651.

The mare lies in an old basin or crater that is within the Procellarum basin. It is 242 kilometers (150 mi) in diameter and 55,000 km (21,000 sq mi) in area, and is bordered to the northeast by the mountain range Montes Apenninus. In the south of the mare is Rima Hyginus, a rille intersected by the crater Hyginus. The lunar material surrounding the mare is from the Lower Imbrian epoch, and the mare material is from the Eratosthenian epoch.

• Mare Vaporum at The Moon Wiki
• Dome in Mare Vaporum - Hook and Dome area
• Wood, Chuck (August 21, 2004). "Vaporum: Crater and Basin". Lunar Photo of the Day.
• Wood, Chuck (September 21, 2008). "A New Look". Lunar Photo of the Day.