This is a list of states in the Holy Roman Empire beginning with the letter J:
| Name | Type | Imperial circle | Imperial diet | History |
|---|---|---|---|---|
 Jagdberg
|
Lordship | |||
 Jauer (Jawor)
|
Duchy | n/a | n/a | 1277: Partitioned from Liegnitz 1281: Partitioned into itself and Löwenberg 1308: Partitioned into Schweidnitz and itself 1346: Extinct; to Schweidnitz |
 Jever
|
1330: Chiefdom Barony |
1353: Formed 1575: Annexed to Oldenburg 1667: Annexed to Anhalt-Zerbst 1793: Annexed to Russia 1806: French occupation 1807: Ceded by Russia to France 1807: To Kingdom of Holland 1810: To France 1814: Russian occupation 1814: Oldenburg administration 1818: Ceded to Oldenburg | ||
 Jülich
|
Duchy | Low Rhen | n/a | 1000s: County 1143: From the Jülichgau 1336: Margraviate 1356: Duchy 1423: United with Berg 1511: United from Cleves-Marck and Jülich-Berg as Jülich-Cleves-Berg 1521: United with Berg, Cleves and Mark 1582: HRE Council of Princes 1609: War of Succession: divided between Brandenburg, Saxony and the Electorate of the Palatinate 1614: Passed to Palatinate-Neuburg 1742: To Dukes of Palatinate-Sulzbach then Bavaria 1794: French occupation 1815: To Prussia |
 Justingen
|
Lordship | Swab | SC | 1090: First mentioned 1343: Extinct; to Stöffeln 1494: To Stotzingen 1497: Sold to Bubenhofen 1530: Sold to Freyberg-Öpfingen 1751: Sold to Württemberg |