U 9

U9 stands for:

• A child checkup

U9 designates the following subway lines:

• Metro Line 9 (Berlin)
• Metro Line 9 (Frankfurt)

U 9 ​​is the name of U- boats:

• SM U 9 (1910-1919), a submarine of the German Imperial Navy
• U 9 ​​( Navy ) ( 1935-1946 ), a submarine of the German Navy
• U 9 ​​(Bundeswehr) ( 1967-1993 ), a submarine of the German Navy

• Disambiguation
• Abbreviation