686 may refer to:

• 686, year 686 AD
• 686 BC
• 686 (number)
• 686 Gersuind, a minor planet orbiting the Sun
• 6-8-6, a wheel arrangement of steam locomotives
• +686, the country calling code for telephone numbers in Kiribati
• Gliese 686, a star in the constellation of Hercules
• Hawaii SB 686, a bill pertaining to cannabis legalization (2019)
• i686, the P6 (sixth-generation) Intel x86 microarchitecture, implemented in the Pentium Pro microprocessor (1995)
• K686, pennant number of Royal Canadian Navy ship HMCS Fergus (1944–1945)
• Kosmos 686, a Soviet satellite launched in 1974
• Minuscule 686, a Greek minuscule manuscript of the New Testament
• Scandinavian Airlines Flight 686, an airplane involved in the Linate Airport disaster (2001)
• Smith & Wesson Model 686, a revolver
• United Nations Security Council Resolution 686, adopted in March 1991 pertaining to Iraq
• USS Eugene E. Elmore (DE-686), a destroyer escort of the United States Navy (1944–1946)
• USS Halsey Powell (DD-686), a destroyer of the United States Navy (1943–1968)
• USS L. Mendel Rivers (SSN-686), an attack submarine of the United States Navy (1975–2001)
• USS Vester (SP-686), a patrol vessel and minesweeper of the United States Navy (1917–1919)
• VLY-686, an experimental drug known as tradipitant

See also

• List of highways numbered 686
• All pages with titles containing 686