Leonia is a residential community in Bergen County, New Jersey. Its name is a reference to American Revolutionary War General Charles Lee, who is also immortalized in the name of the neighboring municipality, Fort Lee, to Leonia's immediate east.

The name was adopted by resident leaders on November 13, 1865, in order to designate the general area served by the Northern Railroad's station (instituted in 1859) and US mail distribution – along Fort Lee Road just east of the Overpeck Creek.

It became incorporated as the Borough of Leonia, Bergen County, on December 5, 1894, at which time it ceased being a loosely defined village in Bergen County's earlier regional divisions known as Hackensack Township and later (from 1871) Ridgefield Township.

1668, however, is the year of the first known dated document referring to territory that is now part of the Borough. On the basis of this item is the claim that Leonia was "settled" 350 years ago.

The area of today's Borough was originally known as and was a part of the larger "English Neighborhood." Broadly speaking, that term covered the land along the eastern side of the Overpeck. The term masks ethnic and linguistic diversity in the region, which was originally inhabited by the Ashkineshacky (Hackensack) Indians, a local branch of the Lenni Lenape nation of Native Americans; the region's earliest European settlers from Holland, whose communities are commonly called "Jersey Dutch"; and the English, some of whom during the Revolutionary War sympathized with continued British rule and others who were allied with the fight for American independence. Gen. George Washington's Retreat of November 20, 1776, went through Leonia.

The Leonia Historic Preservation Commission is tasked with promoting the wellbeing and appreciation of the Borough's historic sites. It operates in conjunction with a public online forum, the Facebook group "I Grew Up in Leonia."

Leonia's oldest historic structures include continuously inhabited homes of pre-Revolutionary, immediately post-Revolutionary, and early and mid-19th century vintage; and a Civil War Armory and Drill Hall, first constructed in 1859, later restored and repurposed to serve as the home of the Players Guild of Leonia. One year shy of a century old, it is New Jersey's oldest continually functioning community theater. To review these and other celebrated addresses, see "Historically Significant Sites" in the Leonia Master Plan.

Over a dozen historic markers can be seen throughout Leonia. Their text and associated landscapes are presented at this nearly complete listing.

View a remarkably rich, searchable collection of Leonia archival material. These items are part of the Local History Collection of the Leonia Public Library. They can be visited in person by appointment.