MWI is the country code for Malawi in several country code systems.

MWI may also refer to:

Science and technology Many-worlds interpretation, in quantum mechanics Message-waiting indicator, in telephony Mobile Web Initiative, in Mobile Web Maths Week Ireland, an all-island (Republic of Ireland and Northern Ireland) mathematics outreach initiative

Other uses Ministry of Water and Irrigation, in Water supply and sanitation in Jordan Warsaw Modlin Airport (IATA: WMI) Mountain Warfare Instructor, in Mountain Warfare Training Center

See also MW-1