Where does “ساو باولو” come from?

ساو باولو (Arabic) comes from Portuguese São Paulo, from Portuguese São, from Old Portuguese são, from Latin sānus, from Proto-Indo-European swā-n- — healthy; whole; active; vigorous.

Ancestry of “ساو باولو”, step by step

Step	Language	Word	Meaning
1	Portuguese	São Paulo	Paul the Apostle, Paul of Tarsus, Saint Paul
2	Portuguese	São	forms the titles of male saints whose names begin...
3	Old Portuguese	são	—
4	Latin	sānus	sound in body, healthy, whole, well
5	Proto-Indo-European	swā-n-	healthy; whole; active; vigorous

Every word from Proto-Indo-European swā-n- →Every word from Latin sānus →Every word from Old Portuguese são →