Like many other towns in the Susa Valley, Oulx has different names reflecting the area's multiple linguistic traditions. One theory of the name's origin is that it derives from Ulkos, the name of a leader of the
Celtic Salassi tribe. Another theory holds that the derivation is from Ultor, a title of the god
Mars, to whom a temple in the area was dedicated. These names were first rendered as
Ulces, and later
Ulcium on maps in the Middle Ages, in
Latin. Today, the municipality is called
Oulx in
Italian and
French,
Ours in the local Cisalpine
Occitan (a
Vivaro-Alpine subdialect; using an alternate orthography),
Ors in standard Occitan (using classical orthography), and
Ols in
Piedmontese as well as in the Cisalpine Occitan standard (using classical orthography). ==Geography==