Royal Astronomical Society -  Publishes journals, awards medals, fellowships and prizes. Houses one of the most comprehensive libraries and archives in the world.

Campaign for Dark Skies (CfDS) - Find out more about the CfDS, what is being done in the U.K., and what you can do to help save our precious skies from light pollution.

Mars Society UK - Working to further the goal of the exploration and settlement of the Red Planet.

Society for the History of Astronomy - Encourages amateur research especially at the local level, and organizes activities. Offers library, publications, projects, news, meetings, and more.

Sheffield Astronomical Society - Features meetings and further information.

Leicester University Astronomy Society - Guides to the night sky: galaxies, clusters, nebulae, stars and planets. Tour the observatories, telescopes, events, the month-by-month calendar and ask an astronomer.

British Astronomical Association - The voice of amateur astronomy in the United Kingdom.