4F

4F or 4-F may refer to:

• 4F (company), a Polish sportswear company
• 4-F classification in the U.S. Selective Service System, identifying a person as unfit for military service
• 4F correlator, in Fourier optics
• The 4f electron shell
• Section 4(f) of the United States DOT act of 1966, which regulates acquiring park and historic properties for transportation use.
• 4F case, a 4 February 2006 controversial criminal case in Barcelona
• Flottille 4F a French naval aviation squadron
• LMS Fowler Class 4F, a class of 0-6-0 steam locomotive
• February 1992 Venezuelan coup d'état attempt, known in Venezuela as "4F".

See also

• F4 (disambiguation)
• Four Fs (disambiguation)