U-9 or U9 may refer to:

• German submarine U-9, the designation of several German U-boats
• U-9, a U.S. Army designation for the Aero Commander 500, a light twin-engined aircraft
• U9, the IATA code for Tatarstan Airlines
• U9 (Berlin U-Bahn), a subway line in Berlin, Germany
• U9, a model of the Motorola ROKR cell phone
• Ascension, a video game
• U9 League, a private university alliance in Taiwan.

• North England Inward Investment Agency
• North English (disambiguation)
• North Entrance
• North Entrance Road Historic District
• Norther Irish coat of arms
• Northerly Island (Chicago)
• Northern 300
• Northern 911
• Northern accent
• Northern Adelaide Waste Management Authority
• Northern Administrative Okrug
• Northern Adventure
• Northern Advocate
• Northern Africa Railway Development
• Northern Alaska
• Northern Alberta Aero Club
• Northern alberta institute of technology
• Northern Alberta kimberlite province
• Northern Alps (disambiguation)
• Northern Altai language
• Northern Altay language
• Northern Amami-Oshima language
• Northern Amateur Football league
• Northern amateur football league
• Northern Amateur League