Are there nonstop flights from London (STN) to Buenos Aires (EZE)?

No. The fastest connection is via Madrid, about 14h 24m of total flying time.

What is the fastest connection from London (STN) to Buenos Aires (EZE)?

via Madrid ≈ 14h 24m, via Paris ≈ 14h 29m, via Barcelona ≈ 14h 44m (estimated flying time, excluding layovers).

from 35,000 ANA miles, from 50,000 JAL miles (economy, one way, based on the published award charts).

London Stansted Airport (STN) to Ezeiza International Airport - Ministro Pistarini (EZE)・11,203 km

No nonstop flights. The fastest connection is via Madrid (MAD), about 14h 24m of flying time (layover not included).

With milesANA 35,000 miles+ (via IST)JAL 50,000 miles+ (via DXB)Economy, one way, estimate. Tap a connection for miles by cabin.

None.

8 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.