Multimission Archive at STScI, a NASA astronomical data archive

Radio masts and towers, poles or lattice towers which carry antennas/aerials

Mast cell, involved in the allergy response

Rick Mast, former NASCAR driver

Marine Academy of Science and Technology, a career academy located in Sandy Hook, New Jersey

Mast (sailing), a pole which holds a sail on sailing ships and boats

Mega Ampere Spherical Tokamak, a nuclear fusion experiment in the UK

Municipal Ambulance Services Trust, an EMS provider in Kansas City, Missouri

Mast (Sufism), in India, a type of religious intoxication

Multi-Application Survivable Tether, an experimental space mission

Military Anti-Shock Trousers, a medical device used to counteract severe blood loss

Austin Mast, botanist

Mast (film) is a 1999 Indian movie by Ram Gopal Verma

Mast (naval), in naval tradition, a non-judicial disciplinary hearing

Mast year, a year in which vegetation produces a significant abundance of fruit

Mast (botany), the edible seed and fruit produced by trees or shrubs that wildlife species will consume