Mid Sussex is an area in the central part of Sussex. It may refer to:

• Mid Sussex District, a local government district in West Sussex
• Mid Sussex (UK Parliament constituency)
• Mid Sussex Football League
• Mid Sussex Times, a local newspaper
• Arun Valley line, also called the Mid Sussex line, a rail line in West Sussex
• More Radio Mid-Sussex, a local radio station
• Brighton & Mid-Sussex, a proposed local government district in the Redcliffe-Maud Report