Yes, Suspiria is definitely a goth band because most of their albums belong to the Darkwave and Gothic Rock genres, which are among the core subgenres of goth music. Albums like The Great And Secret Show, Drama, and Tragedy EP are examples of their goth sound.
Some of the other goth artists that are similar to them are Clan Of Xymox and Rosetta Stone.
Suspiria is located in United Kingdom, England, active in 1993 — present. You can find more information about Suspiria on their GothDB band page.