Are there nonstop flights from Riyadh (RUH) to Islamabad (ISB)?

Yes. Saudia, Flynas, Pakistan International Airlines, flyadeal, airblue, AirSial, Fly Jinnah, Riyadh Air fly this route. Flight time is about 3h 41m.

What is the fastest connection from Riyadh (RUH) to Islamabad (ISB)?

via Dammam ≈ 4h 11m, via Manama ≈ 4h 11m, via Doha ≈ 4h 14m (estimated flying time, excluding layovers).

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

King Khalid International Airport (RUH) to Islamabad International Airport (ISB)・2,699 km

Nonstop flights available (8 airlines). Flight time about 3h 41m. Nonstop return flights also operate.

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

17 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.