Sullah (Bengali: শাল্লা, romanized: Shalla, also spelt Sulla, is an upazila (sub-district) of the Sunamganj District, located in Bangladesh's Sylhet Division.

The local chiefs then re-established the headquarters in the village of Ghungiargaon, located in the centre of Sullah Thana.

Sullah Thana was upgraded to upazila (sub-district) in 1983 as part of the President of Bangladesh Hussain Muhammad Ershad's decentralisation programme.

Sulla had a literacy rate (age 7 and over) of 34.29%, compared to the national average of 51.8%, and a sex ratio of 984 females per 1000 males.

[6][7] Sulla formerly had a Hindu majority, like many other upazilas in the Haor region, but after Partition the Hindus have gradually migrated to India.

[8] Sullah Upazila is divided into four union parishads: Atgaon, Bahara, Habibpur, and Shalla.