The Japanese phenom demolished the record of 255 set last year by Jonathan "Super" Squibb.
The Friday morning extravaganza drew thousands to the Wells Fargo Center before sunrise to watch competitors stuff themselves with chicken wings.
Kobayashi claimed a $20,000 cash prize for his victory. It was the six-time Nathan's Hot Dog eating contest champ's first time competing at Wing Bowl, though he consumed a cheesesteak in 24 seconds as part of an eating exhibition last year.
Squibb had been trying to win his fourth consecutive Wing Bowl crown, but the Berlin, N.J., man finished a distant second with 271 wings.