Are there nonstop flights from London (LHR) to Ronchi dei Legionari/Trieste (TRS)?

No. The fastest connection is via Frankfurt am Main, about 2h 28m of total flying time.

What is the fastest connection from London (LHR) to Ronchi dei Legionari/Trieste (TRS)?

via Frankfurt am Main ≈ 2h 28m, via Milan ≈ 2h 32m, via Hannover ≈ 2h 46m (estimated flying time, excluding layovers).

London Heathrow Airport (LHR) to Trieste Airport (TRS)・1,197 km

No nonstop flights. The fastest connection is via Frankfurt am Main (FRA), about 2h 28m of flying time (layover not included).

None.

14 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.