Diemel

{{Short description|River in Germany}}

{{Infobox river

| name = Diemel

| image = Diemel bei Trendelburg.jpg

| image_caption = The Diemel near Trendelburg

| map = Diemel.png

| source1_location = Sauerland

| source1_coordinates= {{coord|51|15|59|N|8|39|05|E|region:DE-HE}}

| mouth_location = Weser

| mouth_coordinates = {{coord|51|38|33|N|9|26|52|E|display=inline,title}}

| progression = {{RWeser}}

| subdivision_type1 = Country

| subdivision_name1 = Germany

| length = {{convert|110.4|km|abbr=on}} {{GeoQuelle|DE-NW|GSK3C}}

| source1_elevation = {{convert|680|m|abbr=on}}

| discharge1_avg =

| basin_size = {{convert|1,762|km2|abbr=on}} {{GeoQuelle|DE-NW|GSK3C}}

| tributaries_left =

| tributaries_right = Twiste

}}

The Diemel ({{IPA|de|ˈdiːml̩|-|De-Diemel.ogg}}) is a river in Hesse and North Rhine-Westphalia, Germany. It is a western and orographically left tributary of the Weser. It is the first, and therefore southernmost, of the larger Weser tributaries after its formation by the confluence of the Fulda and Werra rivers.