Are there nonstop flights from Rio de Janeiro (SDU) to Buenos Aires (AEP)?

No. The fastest connection is via São Paulo, about 3h 24m of total flying time.

What is the fastest connection from Rio de Janeiro (SDU) to Buenos Aires (AEP)?

via São Paulo ≈ 3h 24m, via Belo Horizonte ≈ 4h, via Brasília ≈ 4h 50m (estimated flying time, excluding layovers).

Santos Dumont Airport (SDU) to Aeroparque Jorge Newbery (AEP)・1,968 km

No nonstop flights. The fastest connection is via São Paulo (GRU), about 3h 24m of flying time (layover not included).

None.

5 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.