The Sagtikos State Parkway is a 5.14-mile (8.27 km) controlled-access parkway in Suffolk County on Long Island, New York, in the United States. It begins at an interchange with the Southern State and Heckscher Parkways in the hamlet of West Islip and goes north to a large cloverleaf interchange with the Northern State Parkway in the Town of Smithtown, where the Sagtikos ends and the road becomes the Sunken Meadow State Parkway. The parkway comprises the southern half of New York State Route 908K (NY 908K), an unsigned reference route, with the Sunken Meadow State Parkway forming the northern portion.

The majority of parkways in the US state of New York are part of a statewide parkway system owned by several public and private agencies but mostly maintained by the New York State Department of Transportation (NYSDOT). A handful of other roads in the Hudson Valley and on Long Island are also known as parkways but are not part of the state system. The roads of the state parkway system were among the first expressways to be constructed. These highways were not divided and allowed no driveway cuts, but did have intersections for some of the streets they crossed. A small section of the privately financed Long Island Motor Parkway was the first expressway to begin operation as a toll road and the first highway to use bridges and overpasses to eliminate intersections.