Lumen

Lumen may refer to:
 * Lumen (unit), the SI unit of luminous flux
 * Lumen (anatomy), the cavity or channel within a tubular structure
 * Lumen (tech company), the health and wellness tech company
 * Lumen (band), a Russian rock band
 * Lumen (branding agency), a design and branding company headquartered in Milan, Italy
 * The Lumen (Cleveland), a skyscraper in downtown Cleveland
 * Lumen (website), a database of Digital Millennium Copyright Act takedown requests
 * 141 Lumen, an asteroid
 * Lumen Martin Winter (1908–1982), American artist
 * Lumen Pierce, a fictional character in the television series Dexter
 * Lumen Technologies, telecommunications company formerly known as CenturyLink
 * Stellar Lumens, a cryptocurrency and payment network
 * USS Lumen (AKA-30), a US Navy ship
 * Lumen, a dating app owned by MagicLab
 * Lumen, an office building in Warsaw, Poland, part of Złote Tarasy complex
 * Lumen, an 1887 novel by Camille Flammarion