Matamoros [US Consulate] — Mexico
Mata-Utu — Wallis and Futuna
Mazatlan — Mexico
Mbabane [US Embassy] — Swaziland
McDonald Islands — Heard Island and McDonald Islands
Medan [US Consulate General] — Indonesia
Mediterranean Sea — Atlantic Ocean
Melbourne [US Consulate General] — Australia
Melilla — Spain
Merida [US Consulate] — Mexico