Land grants were first issued in the Mount Holly area by King George II of Great Britain around 1750. In 1754, a land grant was issued to James Kuykendall of Holland in the locale known as Dutchman's Creek. Later in 1838, a post office in the area was named Woodlawn. In 1875, the name of the town was changed to Mount Holly, after the Mount Holly Cotton Mill that was started that year. The name "Mount Holly" was used in recognition of the famed yarn made at a spinning mill in Mount Holly, New Jersey.
A.P. and D.E. Rhyne and Ambrose Costner originally owned the Mount Holly Cotton Mill. It was the fourth mill to be built in Gaston County and is the oldest surviving mill today. The mill's success and the prosperity of the area as a whole led local residents to petition the North Carolina General Assembly for incorporation of Mount Holly in 1879.
The first railroad in Gaston County, the Carolina Central Railway, began serving Mount Holly in 1860. The line, which runs parallel with North Carolina State Highway 27, is still in service and operated by CSX. In 1911, construction began on the area's second railroad known as the Piedmont and Northern Railway. On May 20, 1912 it made its first run from Charlotte to Gastonia.
Electricity became available to homes and businesses around the turn of the twentieth century. The Woodlawn Mill, located on Woodlawn Avenue, was built in 1906 and was the first mill in Gaston County to be served with electricity.