{{Infobox military conflict
| conflict = Åland Islands War
| image = [[File:Jaakarit vaasan torilla.jpg|250px|]]
| caption = Elements of the 1. Guards Division in Helsinki
| date = 31 January 1921 – 5 September 1928
| place = Åland Islands, Baltic Sea
| combatant1 = '''{{flag|Sweden}}'''
| combatant2 = '''{{flag|Finland}}'''
| commander1 =
 {{unbulleted list
  | {{flag|Sweden}} Gustav V
  | {{flag|Sweden}} Henrik Taube
  | {{flag|Sweden}} Jakob Mörner

 }}
| commander2 =
 {{unbulleted list
  | {{flag|Finland}} Kaarlo Juho Ståhlberg
  | {{flag|Finland}} Paavo Ramsay
  | {{flag|Finland}} Juho Wetzer
  | {{flag|Finland}} Viktor Raappana

 }}
| strength1 = {{unbulleted list |300,000}}
| strength2 = {{unbulleted list |100,000}}
| casualties1 = 191,102
| casualties2 = 40,420
}}