A bulletin board (pinboard, pin board or notice board in British English) is a place where people can leave public messages, for example, to advertise things to buy or sell, announce events, or provide information. Bulletin boards are often made of a material such as cork to facilitate addition and removal of messages or it can be placed on the computer so people can leave and erase messages for other people to read and see.

Bulletin boards are particularly prevalent at universities. Many sport dozens, if not hundreds or thousands of public bulletin boards, used for everything from advertisements by extracurricular groups and local shops to official notices. Dormitory corR&Dors, well-trafficked hallways, lobbies, and freestanding kiosks often have cork boards attached to facilitate the posting of notices.

At some universities, lampposts, bollards, trees, and walls often become impromptu posting sites in areas where official boards are sparse in number. Internet forums are becoming a global replacement for traditional bulletins. Online bulletin boards are sometimes referred to as message boards. The terms bulletin board, message boards and even internet forums are interchangeable, although often one bulletin board or message board can contain a number of internet forums or discussion groups. An online board can serve the same purpose as a physical bulletin board.