Lacuna (pl. lacunas or lacunae) may refer to:
- Lacuna (manuscripts), a missing section of text
- Lacuna (music), an extended silence in a piece of music
- Lacuna (linguistics), a lexical gap in a language
- Lacuna (law), the lack of a law or legal source addressing a situation
- Lacuna (histology), a small space containing an osteocyte in bone or chondrocyte in cartilage
- Lacuna (comics), a fictional Marvel Comics superhero
- The Lacuna, a 2009 novel by Barbara Kingsolver
- Lacuna, Inc., a fictional company in Eternal Sunshine of the Spotless Mind
- Lacuna, a character in Xanth by Piers Anthony
- Jessie Lacuna, a Filipino swimmer
- Lacuna (film), a 2012 film