A Large liquid mirror telescope or (Large LMT) is a technology being pursued by NASA and UBC.

The idea of using a rotating liquid to create a perfect paraboloid was originally proposed by Sir Isaac Newton but the very stringent requirements, in particular on the speed of rotation and leveling, prevented any serious attempt to build a prototype before the second part of the nineteenth century.

Modern LMT research began with Ermanno Borra's paper (Borra 1982). Over several years, the technology was developed successfully to produce a 1.5m diffraction-limited LMT. Then, a collaboration began between Paul Hickson at UBC, and Borra. Hickson designed the 3m-class LMs, and built several 3m-class LMs for UBC, NASA, and UCLA. Hickson and collaborators are now building the 6m LZT located at the UBC Liquid-Mirror Observatory.