In 1818, Matthew, Peter, and William Westervelt, settlers of Dutch extraction, migrated to the area from New York.

Matthew Westervelt donated land for the construction of a Methodist church in 1836, and the settlement was subsequently named in the family's honor.

Benjamin Russell Hanby had moved to Westerville in 1849, at the age of sixteen, to enroll at Otterbein University.

[13] Hanby went on to write many familiar hymns and songs, among them "Darling Nelly Gray" (inspired by his sympathy for Southern slaves[14]), "Who is He in Yonder Stall?

[16] By the 1870s, a burgeoning conflict between pro- and anti-temperance forces boiled over into the so-called "Westerville Whiskey Wars".

Twice, in 1875 and 1879, businessman Henry Corbin opened a saloon in Westerville, and each time the townspeople blew up his establishment with gunpowder.

The League, at the forefront of the Prohibition movement, gained its greatest triumph when the Eighteenth Amendment to the United States Constitution was ratified in 1919.

The League printed so many leaflets in support of temperance and prohibition—over 40 tons of mail per month—that Westerville, by then known as "The Dry Capital of the World", was the smallest town in the nation to have a first class post office.

[18] In 1916, Westerville became the first village (and second municipality)[19] in Ohio to adopt a council-manager form of government, in which a city council makes policy but the town's administrative and many of its executive governmental functions are vested in an appointed, professional manager.

Subsequently, voters have approved alcohol sales in old Westerville at a number of establishments through site-specific local options.

[18][23][24] On October 15, 2019, Westerville hosted the fourth 2020 Democratic Primary Presidential Debate which had over 12 candidates on stage.

[25] In 2020 Westerville was named as the best suburban city in America based on a study conducted by Movoto Real Estate.

The study, which surveyed criteria such as cost of living and crime, compared Westerville to 75 geographically diverse suburban cities across the nation.

Otterbein University, a private four-year liberal arts college, was founded by the United Brethren Church in 1847 and is now home to over 3,000 students.

In the early days before the town's incorporation, Westerville was connected to Columbus by a plank road with a toll of ten cents.

The city itself operates no public buses, but the Central Ohio Transit Authority (COTA) serves Westerville with five bus lines.

[42] T. Marzetti Company and its parent Lancaster Colony Corporation, as well as Mac Tools are headquartered in Westerville.