Ostallgäu is a Landkreis (district) in Swabia, Bavaria, Germany. It is bounded by (from the west and clockwise) the districts of Oberallgäu, Unterallgäu, Augsburg, Landsberg, Weilheim-Schongau and Garmisch-Partenkirchen, and by the Austrian state of Tyrol. The town of Kaufbeuren is enclosed by but does not belong to the district.

Before 1803 the region was split into several tiny states, most of them clerical states. When these states were dissolved in 1803, the Ostallgäu region became part of Bavaria. The kings of Bavaria soon developed a special relationship with the region and built their famous castles of Hohenschwangau and Neuschwanstein there.

The district was established in 1972 by merging the former districts of Kaufbeuren, Marktoberdorf and Füssen.

"Ostallgäu" literally means "Eastern Allgäu". The term Allgäu is applied to the part of the Alps located in Swabia and their northern foothills.

The district extends from the crest of the Alps to hilly countryside in the north. It is located on either side of the Wertach, an affluent of the Lech. In the south there is a great number of alpine lakes, the largest of them being the Forggensee (16 km [6.2 sq mi]).

The coat of arms displays:

• the heraldic lion of the medieval county of Ronsberg
• the sword of Saint Martin, the patron saint of Marktoberdorf
• an abbot's staff representing the Füssen monastery

Towns	Municipalities
Buchloe Füssen Marktoberdorf	Aitrang Baisweil Bidingen Biessenhofen Eggenthal Eisenberg Friesenried Germaringen Görisried Günzach Halblech Hopferau Irsee Jengen Kaltental Kraftisried Lamerdingen Lechbruck Lengenwang Mauerstetten Nesselwang	Obergünzburg Oberostendorf Osterzell Pforzen Pfronten Rettenbach am Auerberg Rieden Rieden am Forggensee Ronsberg Roßhaupten Rückholz Ruderatshofen Schwangau Seeg Stötten Stöttwang Unterthingau Untrasried Waal Wald Westendorf

• Official website (German)
• The online reference book about the Ostallgäu (German)
• Orchids in Allgäu

47°45′N 10°35′E / 47.75°N 10.58°E / 47.75; 10.58