Waikabubak is a town located on the island of Sumba in Indonesia's East Nusa Tenggara province. It serves as the capital of the West Sumba Regency.
Historically, Waikabubak was initially part of the Kupang Regency before it was designated as the capital of South West Sumba in 1913. As of 2002, approximately 6% of the island's total population resided in the town, while it housed about 38% of the region's civil service.