Are there nonstop flights from London (LCY) to Cagliari (CAG)?

No. The fastest connection is via Nice, about 2h 48m of total flying time.

What is the fastest connection from London (LCY) to Cagliari (CAG)?

via Nice ≈ 2h 48m, via Geneva ≈ 2h 49m, via Olbia ≈ 2h 51m (estimated flying time, excluding layovers).

from 25,000 JAL miles (economy, one way, based on the published award charts).

London City Airport (LCY) to Cagliari Elmas Airport (CAG)・1,530 km

No nonstop flights. The fastest connection is via Nice (NCE), about 2h 48m of flying time (layover not included).

With milesJAL 25,000 miles+ (via MAD)Economy, one way, estimate. Tap a connection for miles by cabin.

None.

13 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.