The village of Longside (originally called Peterugie) grew along the edge of the floodplain of the South Ugie Water. Historical reference to farms in the area appears in a 1544 report of a list of the lands belonging to the Abbey of Deer. Building leases were granted by the Laird of Pitfour in 1801, although the parish of Longside was formed much earlier, in 1641, the old church having been built in 1620. The name was derived from the farm on which the church was built, and it is suggested comes from the Gaelic lon : a moss, marsh or meadow.

The principal industry has always been agriculture, mostly mixed farming, with wooded areas and peat moss. A woollen factory was situated at Millbank, but ceased production in 1828. Grey granite was quarried extensively in the past at Cairngall, and transported by rail to many parts of the country, being particularly attractive when polished. The railway, opened in 1862, linked the village with Peterhead, Maud and Aberdeen, thence to the markets of the south. It was closed in 1952.

The Longside Fair, held twice a year in November and May, was the most important "feeing" fair in the area: farm servants offered themselves for hire for the subsequent six months. The place-name "Markethill" commemorates the area covered by the fair which continued until the 1930s.