Interstate 190 (I-190) runs 28.34 miles (45.61 km) from I-90 near Buffalo, New York to Lewiston, New York via Niagara Falls. Parts of this highway were built on the former rights-of-way of the Lehigh Valley Railroad and the Erie Canal. It is referred to by locals as The One-Ninety. Officially, I-190 from I-90 north to New York State Route 384 (NY 384) is named the Niagara Thruway and is part of the New York State Thruway system. The remainder, from NY 384 to Lewiston, is known as the Niagara Expressway (maintained by the New York State Department of Transportation).

I-190 is the only three-digit Interstate Highway to reach the Canadian border. Upon reaching Lewiston, it continues across the Lewiston–Queenston Bridge over the Niagara River and into the Canadian province of Ontario as Highway 405, a short freeway spur to the Queen Elizabeth Way (QEW). I-190 also has an interchange in Buffalo leading to the Peace Bridge, which also crosses the Niagara River into Canada and continues as the QEW on the Canadian side.

I-190 begins at an interchange with the New York State Thruway (I-90) in Cheektowaga in Erie County, just north of the West Seneca town line and east of the Buffalo city line. I-190 heads west into Buffalo, passing the former location of the City Line toll barrier ahead of an interchange with South Ogden Street (exit 1). Farther west, I-190 meets NY 354 (exit 2), NY 16 (exit 3), and several local streets before entering downtown Buffalo. Within the downtown area, I-190 passes between First Niagara Center and Coca-Cola Field near an interchange with NY 5 (exit 7) on the shores of Lake Erie. At NY 5, I-190 turns northward to follow the path of the Niagara River. Shortly after meeting NY 266 (exit 8) immediately northwest of downtown, I-190 interchanges with Porter Avenue (exit 9), a local roadway connecting I-190 to the Peace Bridge and, thus, the Queen Elizabeth Way in Canada.

North of downtown Buffalo, I-190 follows the eastern edge of the Black Rock Canal (and passes the site of the former Black Rock toll barrier) before rejoining the banks of the Niagara near an exit with the Scajaquada Expressway (NY 198, exit 11). I-190 continues north through the northern extents of Buffalo, meeting multiple streets before separating from the Niagara and interchanging with NY 266 and NY 324 (exits 15 and 16) in quick succession. At exit 16, NY 324 joins I-190 northward through western Tonawanda. The two routes then meet I-290 and NY 266 a second time prior to crossing the Niagara River on the South Grand Island Bridge. NY 324 leaves the expressway shortly after arriving on Grand Island at exit 18.

NY 324 and I-190 follow parallel routings across Grand Island, with both roads passing on opposite sides of Martin's Fantasy Island, a local amusement park, near the center of the island. At the northern edge of the island, NY 324, as signed, terminates at exit 20; however, officially, NY 324 rejoins I-190 across the Niagara River once again via the North Grand Island Bridge. Now in Niagara Falls, Niagara County, NY 324 ends at a complex interchange featuring NY 384, the Robert Moses State Parkway, and the LaSalle Expressway on the eastern bank of the river. Farther north, I-190 meets U.S. Route 62 (US 62) at exit 22 and NY 182 at exit 23.

Past NY 182, I-190 turns to the northwest, skirting the northeastern edge of Niagara Falls and roughly paralleling NY 265 to the east. In Lewiston, the expressway meets NY 31 at exit 24 southwest of the large Robert Moses Niagara Power Plant reservoir. I-190 continues onward, crossing the canal between the reservoir and the power plant on a small dam also used by NY 265. The freeway then interchanges with NY 265, the Robert Moses Parkway, and NY 104 at the expansive exit 25 before curving to the west and terminating at the approach to the Lewiston–Queenston Bridge. Across the bridge in Queenston, Ontario, the roadway becomes Highway 405.

The portion of modern I-190 south of NY 384 in Niagara Falls was originally built by the New York State Thruway Authority as part of the New York State Thruway system. Construction on two segments of the highway—from Church Street to Porter Avenue in downtown Buffalo and from Beaver Island Parkway to West River Road on Grand Island—began in the early 1950s. The section in downtown Buffalo was completed by 1954 while the Grand Island portion opened at some point between 1956 and 1958. A short segment of the highway between the Skyway and Church Street was completed around the same time. By 1958, construction had begun on the remainder of the Niagara Thruway. It was completed c. 1961.

On August 14, 1957, the routing of what is now I-190 (including the then-partially complete Niagara Thruway) was originally designated as I-90N. This is because intercity routes—such as I-90N, which connected Buffalo to Canada via Niagara Falls—were numbered before the three-digit Interstates were assigned to the shorter intracity routes. I-90N was renumbered to I-190 on February 24, 1959. Construction on the portion of I-190 north of NY 384 began c. 1962 and was completed by 1964.

In 1991, maintenance of I-84 in downstate New York was transferred from the New York State Department of Transportation (NYSDOT) to the New York State Thruway Authority (NYSTA). The monies for that purpose came from tolls levied on I-190 in downtown Buffalo. Under the laws authorizing the Thruway construction, the tolls were to be removed once the original bonds used to pay for the construction were paid off, which occurred in 1996; however, the tolls would remain for ten more years. Attorney Carl Paladino brought a lawsuit against the state in 2006 to force the removal of the tolls. On October 30, 2006, the Thruway Authority voted to both begin the process of returning maintenance of I-84 to NYSDOT and to remove the tolls on I-190 in Buffalo. Collection of the tolls stopped that day. Both major candidates in the 2006 New York gubernatorial election, Democrat Eliot Spitzer and Republican John Faso, had pledged to remove the tolls on I-190 if elected. While the toll barriers in Buffalo have since been demolished, the tolls further north on the Grand Island bridges still remain.