TLI

TLI may refer to:


 * Thallium(I) iodide, a Thallium compound
 * Transport Layer Interface, a networking application programming interface.
 * Trans-lunar injection, a propulsive maneuver used to set a spacecraft on a trajectory which will arrive at the Moon.
 * Tseng Laboratories, Inc., the full corporate name of Tseng Labs
 * Tall Latte index, an economic index based on the cost of a cup of Starbucks coffee
 * Taipei Language Institute, an institute for teaching Mandarin Chinese founded in 1956
 * The Lonely Island, an American comedy troupe
 * The Living Infinite
 * Trophic level index, an index used in New Zealand for measuring the nutrient content of a lake
 * Term Life Insurance
 * Temporal light interference, undesired degradation or malfunction of an equipment or system caused by light modulations