DOS is a family of IBM PC-compatible operating systems.

DOS or Dos may also refer to:

• Data over signalling (DoS), multiplexing data onto a signalling channel
• Denial-of-service attack (DoS), an attack on a communications network
• Disk operating system
  • List of disk operating systems, Apple DOS, Atari DOS, DOS/360, etc.
• Distributed operating system

• Dos (Altered State album)
• Dos (Dos album)
• Dos (Fanny Lú album)
• Dos (Gerardo album)
• Dos (Malo album), 1972
• Dos (Myriam Hernández album), 1989
• Dos, album by Wooden Shjips, 2009
• ¡Dos!, album by Green Day

• Dos (band), an American rock duo
• DOS (concert), by Filipino singer Daniel Padilla

• Democratic Opposition of Serbia, a former political alliance
• Department of Space, India
• Deutscher Olympischer Sportbund
• Directorate of Overseas Surveys, UK 1957–1984
• Dominus Obsequious Sororium, within the cult NXIVM
• United States Department of State

• Dos, a village in Vidra Commune, Romania

• Density of states in physics
• DOS-1 etc., Russian space station designation in the Salyut programme
• Dioctyl sebacate, an organic chemical
• Diversity oriented synthesis in chemistry

• DOS Kampen, a Dutch football club
• VV DOS, a past Dutch football club now part of FC Utrecht

• Dos (card game), a variation of Uno
• Dos, an Ancient Roman dowry
• Day of Silence, an LGBT observance
• The number 2

• All pages with titles beginning with DOS
• All pages with titles beginning with DoS
• All pages with titles beginning with Dos
• All pages with titles beginning with Do's
• All pages with titles containing do's
• All pages with titles containing dos
• American Descendants of Slavery, ADOS or sometimes DOS
• Doss (disambiguation)
• Do (disambiguation), for the singular of dos