F45 may refer to:
Ships , a Niterói-class frigate of the Brazilian Navy , an armed merchant cruiser of the Royal Navy , a K-class frigate of the Royal Navy , a Leander-class frigate of the Royal Navy , a Talwar-class frigate of the Indian Navy
Aircraft and Airports Firecatcher F-45, a single-turboprop aircraft designed for aerial firefighting, air freight and commuter airlines. Fairchild 45, a rare American 1930s vintage aircraft North Palm Beach County General Aviation Airport, in Florida (location identifier: F45)
Other uses BMW 2 Series (F45), an automobile EMD F45, an American diesel-electric locomotive F45 Training, an Australian multinational chain of fitness clubs Somatic symptom disorder (medical classification code: F45)