Greenwich Hospital is an ancient Crown charity formed when the Royal Hospital for Seamen was established by King William and Queen Mary by Royal Charter in 1694.

The land on which the Royal Hospital (latterly Greenwich Hospital) stands was granted by this charter and formed the core of the extensive Greenwich Estate. Today much of Greenwich town centre, Greenwich Market and part of Greenwich Pier are owned by Greenwich Hospital. The buildings of the Old Royal Naval College (ORNC) are let by the Hospital on a 150-year lease to the Greenwich Foundation.

Greenwich Hospital provides charitable support, including annuities, sheltered housing and education, to serving and retired personnel of the Royal Navy and Royal Marines and their dependants. It supports the Royal Hospital School which was founded in Greenwich in 1712 and moved to Holbrook, near Ipswich, in 1933.

It still adheres to the spirit of its founding charter: the reliefe and support of seamen serving on board the shipps or vessels belonging to the Navy Royall who by reason of Age, Wounds or other disabilities shall be uncapable of further service at sea and being unable to maintain themselves.