| Jurisdiction: | Diocese |
| Speyer | |
| Latin: | Dioecesis Spirensis |
| Local: | Bistum Speyer |
| Country: |  Germany |
| Province: | Bamberg |
| Area Km2: | 6,025 |
| Population: | 1,307,678 |
| Population As Of: | 2010 |
| Catholics: | 616,485 |
| Catholics Percent: | 44.5 |
| Parishes: | 346 |
| Denomination: | Catholic |
| Sui Iuris Church: | Latin Church |
| Rite: | Roman Rite |
| Established: | 4th Century |
| Cathedral: | Speyer Cathedral |
| Patron: | Mary, Mother of God |
| Bishop: | Karl-Heinz Wiesemann Bishop of Speyer |
| Metro Archbishop: | Ludwig Schick Archbishop of Bamberg |
| Auxiliary Bishops: | Otto Georgens |
| Map: | Karte Bistum Speyer.png |
The Diocese of Speyer (Latin: Dioecesis Spirensis) is a Latin diocese of the Catholic Church in Germany. The diocese is located in the South of the Rhineland-Palatinate and comprises also the Saarpfalz district in the east of the Saarland. The bishop's see is in the Palatinate city of Speyer.
The current bishop is Karl-Heinz Wiesemann.
As of 31 December 2006, 44.5% of the population of the diocese was Catholic.
In a slightly different hierarchic structure, it is one of the oldest Dioceses in Germany. A bishop of Speyer was first mentioned in a document in 346. Through grants by the Holy Roman Emperor, the prince-bishops of Speyer established themselves as worldly as well as spiritual rulers. The Diocese of Speyer in its current form was established within the borders of the former Rheinkreis, a district of the Kingdom of Bavaria in 1817 after the secularization and division of the former bishopric in 1803.
For these historical reasons, Speyer belongs to the Province of Bamberg in Bavaria now, even though its territory has no direct border to Bamberg or any other Bamberg suffragan, and is a member of the Episcopal Conference of Bavaria as well as (like all Bavarian bishops) that of Germany.
The current bishop is Karl-Heinz Wiesemann. See also Bishop of Speyer for lists of bishops of the diocese and auxiliary bishops.
The diocese is directed by bishop Karl-Heinz Wiesemann.
The diocese is structured in the following deaneries, with borders that are almost the same as the local county borders:
| Deanery | City / County | Dean | |
| Bad Dürkheim | Priest Michael Paul, Neustadt | ||
| Donnersberg | District Donnersbergkreis | Priest Markus Horbach, Rockenhausen | |
| Germersheim | Priest Jörg Rubeck, Germersheim | ||
| Kaiserslautern | Kaiserslautern city, Kaiserslautern district | Priest Steffen Kühn, Kaiserslautern | |
| Kusel | Priest Michael Kapolka, Schönenberg-Kübelberg | ||
| Landau | Landau city, district Südliche Weinstraße | Priest Axel Brecht, Landau | |
| Ludwigshafen | City of Ludwigshafen | Priest Dominik Geiger, Ludwigshafen | |
| Pirmasens | Pirmasens city, Zweibrücken city, district Südwestpfalz | Priest Johannes Pioth, Pirmasens | |
| Saarpfalz | Saarpfalz district | Priest Eric Klein, Blieskastel-Lautzkirchen | |
| Speyer | City of Speyer, Frankenthal city, district Rhein-Pfalz-Kreis | Priest Pfarrer Markus Hary, Bobenheim-Roxheim |