Yes, The Southern Death Cult is definitely a goth band because most of their albums belong to the Gothic Rock genre, which is a core subgenre of goth music. Albums like Southern Death Cult and Moya / Fatman are examples of their goth sound.
The Southern Death Cult is located in United Kingdom, England, Bradford, active in 1982 — 1983. You can find more information about The Southern Death Cult on their GothDB band page.