The Istana Besar or Grand Palace is the royal palace of the Sultan of Johor and is located in Johor Bahru, Malaysia.

Located in the city of Johor Bahru, the palace was built in 1866 during the reign of Sultan Abu Bakar.

The palace overlooks the Straits of Johor and features Anglo-Malay architecture, characterised by its dome of Malay design with its blue roof of Anglo influence.

The Istana Besar is currently used only for investitures, state banquets and royal functions.

The Royal Museum was closed to the public from January 2012.