Heswall was first recorded in the Domesday Book of 1086 as Eswelle, the property of Robert de Rodelent, who owned much of the eastern side of the Dee. Even earlier, Heswall has been suggested as a possible location for Dingesmere, a place mentioned in Egil's Saga in connection with the great Battle of Brunanburh in 937, in which the Anglo-Saxon king Athelstan defeated a coalition of Norse, Scottish, and Welsh forces. Where exactly Brunanburh was fought has been argued over for a thousand years; Wirral remains one of the leading candidates. In 1277 the manor passed to Patrick de Haselwall, who became Sheriff of Cheshire. The name of the village has shifted across the centuries: Hestlewelle, Hesselwelle, and finally, only after 1897, settled into the modern Heswall.

The oldest piece of Heswall above ground is the tower of St Peter's Parish Church, around five centuries old, the only surviving fragment of the previous church on the site. That earlier church was destroyed in dramatic fashion on 19 September 1875, when a violent thunderstorm rolled over the Wirral. Lightning struck the church during a service. The organist and the boy who pumped the bellows for the organ were both killed. The current church was rebuilt by 1879, the third on the site. A short walk back up Telegraph Road, near the Gayton Roundabout, the stump of Gayton's windmill still stands, converted into a private house. The mill ground its last sack of flour in 1860. Its tower has been a Heswall landmark for longer than most of the streets around it.

Heswall's transformation from farming village to commuter town happened fast. In 1801 the population was 168. By 1841 it had reached 398. Then the Borderlands Line from Wrexham to Bidston opened in 1896, and a second line from West Kirby to Hooton already ran below the village, and the wealthy merchants who had once kept country houses here started to live in them year-round. The houses got larger, the gardens longer, the gates higher. The neighbouring villages of Gayton, Heswall, Pensby, and Thingwall grew together into one continuous suburb. By 2001 Heswall was listed as the seventh-richest neighbourhood in the United Kingdom. The median house price in 2022 was £409,500, the most expensive on the Wirral. The 2021 population stood at 29,075, the figures of a small town that thinks of itself as a village.

What makes Heswall feel like more than a commuter postcode is the land below it. The Dales is a stretch of dry sandy heathland that drops down the hillside toward the Dee, a Site of Special Scientific Interest and Local Nature Reserve, with a small valley called the Dungeon cut into the slope. A path from the Dales leads to the Wirral Way (the old railway trackbed, closed in 1956) and from there to the foreshore, where the Dee runs out for miles at low tide. Poll Hill, near the centre of Heswall, is the highest point on the Wirral Peninsula. From its summit on a clear day the view runs all the way across the estuary to the Clwydian Range. The Beacons, another open area along the ridge, were once warning fires lit to summon Wirral men to muster.

The list of people who have called Heswall home is improbable for a town its size. The disc jockey John Peel, who through Radio 1 introduced Britain to almost every important musical movement from the late 1960s to the early 2000s, was born here. The cricketer Ian Botham, Lord Botham, was born here too. Ian Astbury of The Cult and Andy McCluskey of Orchestral Manoeuvres in the Dark were both born in Heswall. Stephen Hough, the concert pianist, is from Heswall. So is Bill Steer of Carcass, the death metal band. Philip May, husband of former Prime Minister Theresa May, grew up here. Most famously, Paul McCartney bought his father Jim a detached mock-Tudor house called Rembrandt on Baskervyle Road in 1964, for £8,750. Jim McCartney lived in Heswall until his death on 18 March 1976. There is no plaque on the house. There is, sometimes, a knot of Beatles fans on the pavement, looking at the curtains.