Are there nonstop flights from Rio de Janeiro (SDU) to Porto (OPO)?

No. The fastest connection is via São Paulo, about 11h 1m of total flying time.

What is the fastest connection from Rio de Janeiro (SDU) to Porto (OPO)?

via São Paulo ≈ 11h 1m, via Campinas ≈ 11h 6m (estimated flying time, excluding layovers).

Santos Dumont Airport (SDU) to Francisco de Sá Carneiro Airport (OPO)・7,971 km

No nonstop flights. The fastest connection is via São Paulo (GRU), about 11h 1m of flying time (layover not included).

None.

2 one-stop options, sorted by estimated flying time. Tap one to see the airlines on each leg and booking links.

Times are estimated from distance. Check schedules, frequency and availability with the airline or a booking site.