NY 63 was assigned as part of the 1930 renumbering of state highways in New York, but to a largely different routing than it follows today.

The original alignment of NY 63 was identical to its current alignment between Mount Morris and Pavilion; however, the route deviated significantly from its modern routing past those points as it extended southwest from Mount Morris to Hinsdale and north from Pavilion to Hamlin.

Another long, open stretch brings the route to the vicinity of the village of Mount Morris, where it runs much closer to I-390 and indirectly connects to the expressway by way of NY 408 at Hampton Corners.

This next section of highway has become a major shortcut for traffic heading to the Buffalo area, despite remaining a two-lane road through open rural country, since it is both physically shorter than going all the way to the New York State Thruway as well as toll-free.

[3] From Greigsville, the route heads west through open land into the northeast corner of Wyoming County and the town of Covington.

From Peoria, NY 63 runs across rolling, open terrain to the Genesee County line and the town of Pavilion.

After the traffic light at the center of the hamlet, NY 63 crosses Oatka Creek and climbs back up out of the Wyoming Valley.

[3] Past Alabama, NY 63 continues northward across the Iroquois National Wildlife Refuge and into Orleans County.

The latter highway continues eastward while the former joins NY 63 through the village's historic central district on Main Street.

NY 63 continues northwest on Main and Commercial streets to the edge of the village, where it turns northward onto Prospect Avenue and subsequently crosses over the Erie Canal.

[6] For the next 3 miles (4.8 km), the highway serves a stretch of scattered homes along the western bank of Oak Orchard Creek.

NY 63 briefly overlaps the east–west trunk road before resuming a northerly, downhill alignment toward the town of Yates.

Route 30 originally followed current NY 31 to Rochester;[7][8] however, it was realigned on March 1, 1921, to use Ridge Road instead, bypassing the Medina–Ridgeway highway.

[10][11] By 1926, all numbered portions of current NY 63 were state-maintained, as were the unnumbered parts from Geneseo to Piffard and from Groveland to Hampton Corners.

[6] As part of a large scale study in the early 2000s, NYSDOT determined that NY 63 from Mount Morris to Pavilion, along with US 20 and NY 77—termed the "Route 63 Corridor"—were major trouble routes, primarily because of increased truck traffic using the corridor as a bypass between I-390 in Mount Morris and the New York State Thruway in Pembroke.

[4] The most publicized and perhaps most fought-over possibility mentioned was that of a new expressway[27] from Mount Morris to Pembroke, bypassing these three routes.

The Wyoming County Chamber of Commerce was a driving force behind this, hoping interchanges in Perry, Warsaw and Attica would promote business growth.

The general consensus of all of these groups is that NYSDOT should impose restrictions on the NY 63 corridor and force trucks to remain on I-390 and the Thruway to travel between Buffalo and Pennsylvania.