This is a list of states in the Holy Roman Empire beginning with the letter U:
| Name | Type | Imperial circle | Imperial diet | History |
|---|---|---|---|---|
 Überlingen | Imperial City | Swab | SW | 1268: Free Imperial City 1803: To Baden |
 Ulm | Imperial City | Swab | SW | 1115: Free Imperial City 1802: To Bavaria 1810: To Württemberg |
 Umpfenbach | Territory | n/a | n/a | n/a 1773: Purchased by Philipp Freiherr von Gudenus and Valentin Ferdinand Freiherr von Gudenus from Christian Friedrich Carl Graf zu Castell-Remlingen [1] June 1, 1805: Purchased by Ferdinand von Trauttmansdorff from Ferdinand Freiherr von Gudenus [2] |
 Unterwalden | Imperial Valley | n/a | n/a | Divided into Nidwalden and Obwalden from an early date 1173: To Counts of Habsburg 1291: Became a founding member of the Swiss League 1324: Imperial immediacy By 1350: Permanent division into Obwalden and Nidwalden 1648: Left Empire as member of Swiss Confederation |
 Upper Alsace (Sundgau; Oberelsaß) | Landgraviate | n/a | n/a | 1130: To Habsburg 1469: Sold to Burgundy 1477: To the Burgundian Netherlands 1516: To Austria 1648: To France |
 Upper Bavaria (Oberbayern) | Duchy | n/a | n/a | 1255: Partitioned from Bavaria 1314: Partitioned into the Palatinate and itself 1340: Renamed to Bavaria 1349: Partitioned from Bavaria 1363: Extinct; to Bavaria-Landshut |
 Upper Salm See: Salm in the Vosges County | ||||
 Urach | County | n/a | n/a | 1040: First mentioned; brother of Achalm c. 1080: First use of title Count of Urach 1098: Acquired Achalm 1218: Acquired Freiburg 1250: Partitioned into Freiburg, itself and Fürstenberg 1261: Extinct; to Fürstenberg 1265: Sold to Württemberg |
 Uri | Imperial Valley | n/a | n/a | 853: To Fraumünster Abbey as part of Swabia 12th Century: To Zähringen 1218: To Habsburg 1231: Free Imperial Valley 1291: Became a founding member of the Swiss League 1648: Left Empire as member of Swiss Confederation |
 Ursberg | Abbacy | Swab | SP | 1126-8: Founded 1143: Imperial immediacy 1803: To Bavaria |
 Ursin von RosenbergSee: Orsini-Rosenberg | Principality | |||
 Utrecht | Bishopric | Low Rhen | n/a | 695: Diocese established 1024: HRE Prince of the Empire 1528: Secularised as the Lordship of Utrecht; to the Spanish Netherlands |
| Utrecht | Lordship | Burg | n/a | 1528: Bishopric of Utrecht secularised; to the Spanish Netherlands 1548: Transferred to the Burgundian Circle 1579: Dutch Revolt against Spain 1648: Left the Empire as part of the Netherlands |
 Uznach | Lordship 1209: County | n/a | n/a | 12th Century: To Rapperswil 1195: To Toggenburg 1209: HRE Count 1436: To Raron; disputed by Zürich 1469: Sold to Schwyz and Glarus in condominium 1648: Left the Empire as part of Switzerland |
