Neptunia

Neptunia may refer to:


 * Neptunia (plant), a genus of plants within the subfamily Mimoseae
 * Neptunia (gastropod), an emendation of Neptunea, a genus of sea snails
 * Neptunia (Darkwing Duck), a cartoon character in the television series Darkwing Duck
 * Neptunia, Uruguay, a resort location in Canelones Department, Uruguay
 * MS Neptunia, an Italian liner launched in 1931
 * MV Neptunia, an Italian tanker launched in 1945
 * Hyperdimension Neptunia, a video game series
 * Neptunia, a Roman colony at Taranto, Italy