John Mein may refer to:

• John Gordon Mein, U.S. ambassador
• John Mein (publisher)

• Flagler Saints
• Flagler Saints baseball
• Flagless vessel
• Flaglor Sky Scooter
• Flagman Ahead
• Flagmast
• Flag match
• Flagmen of Lowestoft
• FLAG-Mito
• FLAG-MITO
• Flag of Aargau
• Flag of Abu Dhabi
• Flag of Abu Dhabi (emirate)
• Flag of Adélie Land
• Flag of African Union
• Flag of Ajman
• Flag of Akershus
• Flag of al-Qaeda
• Flag of Alsace
• Flag of Anglesey
• Flag of Anglo-Egyptian Sudan
• Flag of Anjouan
• Flag of Antarctica
• Flag of Antigua & Barbuda
• Flag of Aquitaine