Star KO (abbreviated as Star-Knockout and Star Finsh) is a type of KO that occurs when a character is knocked beyond the upper blast line (save for a few exceptions, see below), they fly through the background, yell/scream/etc, and eventually disappear as a star. There is also a random chance of a Screen KO instead, where the opponent hits the camera.
Star KO's are usually the longest type of KO, so they usually protect their perpetrator more from the victim's revenge.
In Super Smash Bros., members of a team (such as the Fighting Polygon Team) do get Star KO'd. In Melee, members of a computer team (such as the Fighting Wire Frames) don't experience Star KOs, instead undergoing the usual colorful explosion (However, in Event Match 37, they can get Star KO'd). Also, in the beginning of the second trailer for Super Smash Bros. Brawl, Kirby uses his up smash to knock Mario and Link off the top of the screen, but the usual colored explosion occurs, instead of a Star KO. The Star KO is still in this game. As mentioned above, sometimes a Screen KO will happen instead. According to Sakurai, Star KOs return in Super Smash Bros. for Nintendo 3DS/Wii U, however, they will not occur when the time limit is almost reached. The animation for Star KOs are slightly different in Super Smash Bros. Ultimate. Characters will do their tumbling animation facing the screen, although some, like Little Mac, appear to still tumble facing left. In addition, they become much smaller as they're falling right before disappearing as a star.
- Star KO: Star KO an opponent.
- Solar Being: Get star KO'd.
- Comet Mystic: Get Star KO'd with an opponent.
- The Star KO could be a reference to the Pokémon anime series, as when Team Rocket gets defeated, they tend to (but not always) get sent flying and shout "We're blasting off again!" before vanishing into a star.
- Star KO's have appeared in other media, their process being similar to in the Pokémon series.
- Any conditions on the character are seen in the Star KO, such as if a character is KO'd while frozen, or has a Smash Ball when they are KO'd. In Flat Zone 2 and Hanenbow, conditions are not aligned with the character (i.e. the frozen block and character fly off separately).
- Giant/tiny characters who are Star KO'd remain giant/tiny while falling on the background (their "falling voice" remains deep/tiny as well). On the other hand, Star KO'd metal characters appear in normal conditions on the background (inc. voice). The only exceptions are the Metal opponents in Melee's 1 Player modes. In Super Smash Bros. Brawl, when giant/tiny characters gets Star KO'd, they will return to normal size.
- If Kirby has copied another fighter's abilities and gets Star KO'd, he will appear as a normal Kirby while disappearing into the background.
- While it is generally impossible to self-destruct as a Star KO, there are a few ways: one can stand on a platform above the upper blast line or get launched upwards by Pikachu's Quick Attack in the highest platform of Hyrule Castle (only in Super Smash Bros.), Wario's fully charged Wario Waft, Snake's C4, Jigglypuff's Shield Jump, or two timed Sonic using the Homing Attack.
- Strangely, being carried off the upper blast line with Fox, Falco, or Wolf's Landmaster will result in a Star KO, even though you do not suffer damage or knockback from being carried. Because of this, though, the fighter's Landmaster will not get the KO; it will count as a self-destruct or go to whoever damaged the KO'd character last.
- If King Dedede is Star KO'd while using his Down Air Attack, the respective sound will remain until he disappears.
- Star KOs were not seen in the trailers in Super Smash Bros. for Nintendo 3DS/Wii U, because the game was still in development.
- However, they appeared in the E3 2014 gameplay, although it was sometimes shown, and other times they were KO'd upwards with Blast KOs.
- Ultimate marks the first time a character actually says something during a Star KO other than screaming. When Star KO'd, Pit, will yell out "I never learned how to reaaaaad!" instead of yelling. He is the only fighter that does this. (Not even his Echo Fighter, Dark Pit, does this. He just grunts as he did in his Super Smash Bros. debut.)