Originally part of Plum Township, Oakmont was created out of the second ward of Verona in 1889. It took its name from the oak trees in the area.

Oakmont residents originally filed for incorporation in 1886, but the final decision was delayed for nearly three years because Verona opposed it. Some residents initially wanted to call the new community Hulton after Jonathan Hulton, an early settler who operated a ferry across the Allegheny River in the area of the Hulton Bridge.

One of the earliest developments in the area occurred in 1749, when land speculator George Croghan bought a large tract from Shawnee, Iroquois and Delaware Indians. The land included most of what is now Pittsburgh, Swissvale, Rankin, Edgewood, Wilkinsburg, Churchill, Verona and Oakmont.

Thomas Girty bought part of that land and established a trading post in 1776 on Plum Creek. In 1802, he sold some of the land to Presley Neville. About 500 acres in Oakmont also was owned by Gen. Richard Butler, who was killed in the Indian War of 1791.

In 1816, Michael Bright bought 234 acres and moved from Pittsburgh with his wife and 16 children to what is now Oakmont. The brick house he built still stands at 101 Pennsylvania Ave.

Bright and his wife, Barbara, are buried in a cemetery he established on Fourth Street, between Pennsylvania and Maryland avenues.

By 1834, only 15 people lived in the area, many of them members of the Bright family. That year, Hulton bought a 60-acre tract and established a farm near what is now Hulton Road. His son, James, helped operate the river ferry.

By 1842, Caleb Lee had purchased most of what is now the northern end of Oakmont.

Hulton was the first postmaster in the area and gave his name to the Allegheny Valley Railroad station in Oakmont. The railroad, which opened in 1853, was the biggest factor in the borough's growth.

James Hulton's son-in-law, William Braithwait, built Oakmont Carnegie Library and St. Thomas Episcopal Church, funded by prominent citizen Jacob W. Paul in honor of his wife. Helen Keller received her first formal education at a "young ladies finishing school" in the Wade house on Hulton Road.

The area's population grew to about 1,550 by 1870. The Agnew Glass Co. moved into the area that year, one of the first examples of manufacturing facilities relocating from Pittsburgh to outlying areas. That was followed over the next few years by companies making wagons, springs and specialty tin items.