U.S. Route 111 (US 111) was a U.S. Highway that extended from Baltimore, Maryland north to the Harrisburg, Pennsylvania area.

[1][2][3] This route description features US 111 as it existed in 1945, with references to today's highways to provide context.

US 111 left Baltimore and continued to Towson, where the highway entered downtown by passing under the Maryland and Pennsylvania Railroad at the modern MD 45–Towsontown Boulevard intersection.

US 111 continued north through Lutherville, where the route met the eastern end of MD 131 (Seminary Avenue), and Timonium.

In Cockeysville, the highway met the western end of MD 143 (Warren Road) and passed under the Northern Central Railway at an oblique angle, but did not intersect MD 145 (Ashland Road), which did not yet extend west of Loch Raven Reservoir.

The U.S. highway met the eastern end of MD 409 (Freeland Road) before crossing the Mason–Dixon Line into Pennsylvania.

US 111 continued north from the state line along what is now SR 3001 (Susquehanna Trail) all the way to the city limits of York.

The U.S. Highway had a few tight curves as it descended a hill just south of where the road now crosses the Pennsylvania Turnpike.

US 111 passed along the edge of the village of New Market and crossed the York–Cumberland county line at Yellow Breeches Creek.

US 111 crossed over the Pennsylvania Railroad immediately before reaching its northern terminus at US 11 and US 15 (Market Street), which is today SR 1010.

[5] It did not continue into New York due to the insistence of Frederick S. Greene of that state to designate only the most major highways, "thinking that [other states] wanted to justify their great amount of roads by having New York pursue the same ridiculous policy.

By April 1927, Pennsylvania and AASHO had come to an agreement: US 111 was extended north, concurrent with US 11 and US 120 to Williamsport, where it took over former US 220 to New York.

[9] US 111 was extended beyond its northern terminus at the Mason-Dixon line to Lemoyne; it ran concurrent with US 11 to Northumberland.

U.S. Route 120 also passed through Northimberland on the present alignment of PA 147, running concurrent with US 111 to Williamsport.

[1][3] Soon after 1940, US 15 was rerouted to roughly its present alignment, only crossing the Susquehanna River once - on the Market Street Bridge at Williamsport.

[2][13] Later changes to US 111 included an extension to Front Street and Walnut Street in Wormleysburg when US 11 was moved to its present alignment, relocations to the new freeway (now I-83) south of Lemoyne, and finally a relocation from Lemoyne over the John Harris Bridge with I-83 to end at U.S. Route 22 in Lower Paxton Township.

[15] On December 1, 1962, the American Association of State Highway Officials approved the elimination of the US 111 designation.

was an alternate route of US 111 that ran through York, Pennsylvania, while US 111 bypassed the city to the east along I-83.

The route narrowed to an undivided road and headed north into York along South George Street.