The Maryland Ornithological Society (MOS) is a nonprofit, statewide organization of people who are interested in birds and nature. It was founded in 1945 and incorporated in 1956 to promote the study and enjoyment of birds. MOS promotes knowledge about our natural resources, and fosters its appreciation and conservation. The Society also maintains a system of sanctuaries to encourage the conservation of birds and bird habitat, and to help record and publish observations of bird life.

Local chapters throughout the state offer field trips, bird counts, and conservation projects for members and guests. Lively and informative programs complement regular meetings where members and guest speakers share their knowledge and expertise.