Are there nonstop flights from Rijeka (RJK) to London (LHR)?

No. The fastest connection is via Zurich, about 2h 33m of total flying time.

What is the fastest connection from Rijeka (RJK) to London (LHR)?

via Zurich ≈ 2h 33m, via Stuttgart ≈ 2h 33m, via Munich ≈ 2h 35m (estimated flying time, excluding layovers).

from 15,000 ANA miles (economy, one way, based on the published award charts).

Rijeka Airport (RJK) to London Heathrow Airport (LHR)・1,307 km

No nonstop flights. The fastest connection is via Zurich (ZRH), about 2h 33m of flying time (layover not included).

With milesANA 15,000 miles+ (via ZRH)Economy, one way, estimate. Tap a connection for miles by cabin.

None.

10 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.