Bone fragments and tools, representing the earliest humans known to have lived in England, have been found from 1935 onwards at the Barnfield Pit about 2 km (1 mile) outside the village.

Lower levels of the Barnfield Pit yielded evidence of an even earlier, more primitive, human, dubbed Clactonian Man.

[5][6] During archaeological work undertaken at Ebbsfleet, before construction of High Speed 1, an Anglo-Saxon mill and a Roman villa were found near Swanscombe.

From Crayford to the Isle of Thanet the Danes occupied the land and terrorised the Saxon inhabitants, giving rise to the appearance of Deneholes, of which many have survived to this day.

It is claimed, apparently without evidence, that in 1066 Swanscombe locals massed an army in defiance of William I and so won the right to continue their ancient privileges, including the tradition of passing inheritance by gavelkind.

It survives as a rare example of his design, covering several Gothic Revival styles throughout its architecture and features, such as Decorated tracery on the windows and Arts and Crafts Perpendicular woodwork in the interior.

[9] Just after 8 o'clock in the evening of Sunday 10 November 1940 a German bomb crashed down direct into The Morning Star Inn, causing in a single explosion Swanscombe's worst wartime disaster.

All that was left after the explosion was, where the pub had stood, a "heap of bricks and twisted rafters"¹ surrounding the smouldering pit that had been the cellar, although the staircase leading to the clubroom upstairs extended up out of the wreckage.

Distressed families of those known to be in the pub at the time gathered at the street corners awaiting news of the casualties as bodies were gradually recovered from the ruins.

Its proximity to London and position under the German flight path to the city meant that Swanscombe fell victim to this kind of damage several times during the war.

[11] On 10 April 2023, Galley Hill, Swanscombe, was closed because part of the chalk cliff supporting the A226 collapsed on Easter Monday, taking some of the road with it, near the old George & Dragon pub.

The Swanscombe plant was subsequently acquired by John Bazley White & Co, which became the largest component of Blue Circle Industries when it formed in 1900.

However, the neighbouring Medway towns are reported to be the most polluted inhabited area in the UK, and the cement industry contributes to acid rain in Scandinavia[citation needed].

The Associated Portland Cement Manufacturers (APCM), later known as Blue Circle Industries, came to the area in 1900 and by 1920 owned four local factories located at Swanscombe, Northfleet, Greenhithe and Stone.

[17] The skeleton of an ancient species of elephant has been preserved in the sediment near what was once the edge of a quite small lake revealed by excavations in advance of the Channel Tunnel Rail Link.

The Swanscombe example was discovered in 2004 by Palaeolithic archaeologist Francis Wenban-Smith and was identified by the Natural History Museum as the straight-tusked Palaeoloxodon antiquus, which became extinct more than 100,000 years ago.

The sector of employment of residents was 21.6% retail, 9.3% health and social work, 15.7% manufacturing, 10.5% construction, 10.4% real estate, 4.7% education, 8.6% transport and communications, 4.7% public administration, 3.7% hotels and restaurants, 4.4% finance, 0.7% agriculture and 5.7% other.

Swanscombe is served by Arriva Kent Thameside routes 306, 480, 483, and ArrivaClick, which connect it with Bluewater, Dartford, Ebbsfleet, Gravesend, Greenhithe and Northfleet.