| Südtondern | |
| Native Name Lang: | de |
| Settlement Type: | Amt |
| Subdivision Type: | Country |
| Subdivision Name: | Germany |
| Subdivision Type2: | State |
| Subdivision Name2: | Schleswig-Holstein |
| Subdivision Type3: | District |
| Subdivision Name3: | Nordfriesland |
| Seat Type: | Region seat |
| Seat: | Niebüll |
| Leader Title: | Amtsdirektor |
| Leader Name: | Dr. Wolfgang Sappert |
| Area Total Km2: | 594,45 |
| Population Total: | 40.113 |
| Population As Of: | 2020-12-31 |
| Website: | www.amt-suedtondern.de |
Südtondern is an Amt ("collective municipality") in the district of Nordfriesland, in Schleswig-Holstein, Germany.
Its seat is in Niebüll. It was formed on 1 January 2008 from the former Ämter Bökingharde, Karrharde, Süderlügum and Wiedingharde, and the municipalities Niebüll and Leck.
In addition to the main seat in Niebüll, there are offices in Leck, Risum-Lindholm and Süderlügum.
The Amt Südtondern consists of the following municipalities: