Sirindhorn (Thai: สิรินธร; RTGS: Sirinthon) is a district (amphoe) of Ubon Ratchathani province, Thailand, established by the Royal Decree Establishing Amphoe Sirindhorn, BE 2534 (1991), coming into force on 4 January 1992.

The district was created effective 3 January 1992 by splitting off tambon Kham Khuean Kaeo from Khong Chiam and the five tambons, Khan Rai, Chong Mek, Nikhom Sang Ton-eng Lam Dom Noi, Non Ko, and Fang Kham, from Phibun Mangsahan.

[1] Neighboring districts are (from the south clockwise): Buntharik, Phibun Mangsahan and Khong Chiam.

There is a border crossing to Laos here—from Chong Mek on the Thai side to Vang Tao on the Lao side, with onward travel typically to Pakxe.

The district is divided into six subdistricts (tambons), which are further subdivided into 76 administrative villages (mubans).