James Glaisher was an English meteorologist and aeronaut (April 7, 1809 - February 7, 1903).

Educated at St Paul's School in London, and Trinity College, Cambridge, Glaisher was an assistant at the Royal Greenwich Observatories at Cambridge and Greenwich, and Superintendent of the Department of Meteorology and Magnetism at Greenwich for thirty-four years.

In 1845, Glaisher published his dew point tables, for the measurement of humidity.

Glaisher was a founder member of the Meteorological Society (1850), and the Aeronautical Society of Great Britain (1866).

He is most famous, however, as a pioneering balloonist. Between 1862 and 1866, usually with Henry Tracey Coxwell as his co-pilot, Glaisher made numerous ascents in order to measure the temperature and humidity of the atmosphere at its highest levels. One one ascent in 1862, he broke the world record for altitude, but passed out before a reading could be taken. Estimates suggest that he rose to approximately 7 miles above sea-level.