Blackout may refer to:

In electricity distribution:

• A power outage, a large-scale disruption in electric power supply
• Blackout (wartime), a reduction in lighting to protect a place from enemy attack

In medicine:

• An episode of fainting, a syncope (medical term), g-LOC (associated with flying) and possibly with a precursor greyout or brownout.
• The choking game, a dangerous, sometimes fatal, activity adolescents and teenagers partake in where oxygen and/or blood supply to the brain are compromised for a 'rush'
• A blackout is a term associated with the amnesia caused by the effects of alcohol
• A phenomenon known as shallow water blackout and deep water blackout

In communications or telecommunications:

• Communications blackout, a military tactic of avoiding use of radio communication in an attempt to "hide" from the enemy
• Blackout (broadcasting), a regulatory ban, or embargo, on the broadcasting of an event, for example a television network may not be allowed to show a sporting event to a certain region or a press release is not permitted to be broadcast until a certain date and time.

In sport, entertainment and publishing:

• In theatre, a blackout is the act of turning off all the stage lights, for some duration, for dramatic reasons. Acts will frequently end with a blackout
• Blackout (entertainer), the stage name of actor/singer/radio DJ Michael Bigansky ^*
• Blackout (The Scorpions album), a 1982 album and song by The Scorpions
• Blackout (The Hed P.E. Album), a 2003 album by Hed P.E.
• Blackout (Dropkick Murphys album), a 2003 album by Dropkick Murphys
• Blackout (game show), an American game show that briefly aired on CBS
• Blackout, an independent wrestling stable in Combat Zone Wrestling whose members are Joker, Eddie Kingston, Ruckus and Sabian
• Blackout (Buffy novel), a Buffy novel about the character Nikki Wood
• Blackout Comics, a comic company owns Hari Kari
• Blackout, Marvel characters.
• Oh Hell, an easy-to-learn trick-taking card game nicknamed "Blackout"

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