Ultra-high temperature processing, (less often) ultra-heat treatment (both abbreviated UHT), or ultra-pasteurization is the sterilization of food by heating it for an extremely short period, around 1-2 seconds, at a temperature exceeding 135°C (275°F), which is the temperature required to kill spores in milk.

The most common UHT product is milk, but the process is also used for fruit juices, cream, soy milk, yogurt, wine, soups, honey, and stews.

UHT product has a typical shelf life of six to nine months, until opened.