Petrolia sits about 30km southeast of Sarnia and 100km west of London, Ontario. There's no passenger rail service; the nearest train stations are in Sarnia and London.
By car, it's a short drive off Highway 402 (the Sarnia–London route), which makes Petrolia an easy stop on a longer trip. Most visitors come from Toronto (about 3 hours), London (1 hour), or as a day trip from Sarnia (30 minutes).