Doublet may refer to:

• Doublet (clothing), a man's snug-fitting buttoned jacket that was worn from the late 14th century to the mid 17th century
• Doublet (lapidary), an assembled gem composed in two sections, such as a garnet overlaying green glass
• Doublet (lens), a type of lens, made up of two stacked layers with different refractive indices
• Doublet (linguistics), one of two or more words of the same language that come from the same root
• Doublet (physics), a quantum state of a system with a spin of 1/2
• Pierre Jean Louis Ovide Doublet (1749 - 1824), a politician and writer from France
• Word ladder or "Doublets", a word game invented by Lewis Carroll
• In mathematics, the unit doublet is the derivative of the Dirac delta function
• In textual criticism, two different narrative accounts of the same actual event
• Dimeresia howellii, a tiny flowering plant.

fr:Doublet pl:Dublet