Are there nonstop flights from New York (LGA) to Washington (IAD)?

Yes. United Express fly this route. Flight time is about 56m.

What is the fastest connection from New York (LGA) to Washington (IAD)?

via Charlottesville ≈ 1h 44m, via Richmond ≈ 1h 44m, via Norfolk ≈ 1h 52m (estimated flying time, excluding layovers).

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

LaGuardia Airport (LGA) to Washington Dulles International Airport (IAD)・367 km

Nonstop flights available (1 airline). Flight time about 56m. Nonstop return flights also operate.

With milesANA 15,000 miles+ (via YYZ)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.