The car's foundations lay in the Atom, an Aston Martin project developed during World War II. Its tube-frame chassis and 2.0-litre four-cylinder engine were both developed by Claude Hill. The Atom was never put into production itself but served as the technical starting point for what would become the company's first post-war road car under new ownership.
Shortly after David Brown purchased Aston Martin, construction began on an updated version of the Atom. To test the new car's durability, this prototype was entered in the 24-hour race at Spa in 1948, where it won outright with drivers St. John Horsfall and Leslie Johnson — a decisive proof of concept for the fledgling programme.
The Spa race car was rebuilt and exhibited at the London Motor Show as an example of a proposed Spa Replica series intended for public sale. There were no buyers. The single Spa car was kept for many years in the Dutch Motor Museum; in 2006 it returned to the United Kingdom and was fully restored.
Alongside the cycle-wing Spa car, David Brown directed Aston Martin to build a two-seat roadster with a more conventional body for the London show. This was the 2-Litre Sports proper. It used the same 2.0-litre Claude Hill engine, rated at 90 hp (67 kW), which was sufficient to propel the small, light vehicle to 93 mph (150 km/h).
Thirteen of the cars wore the open roadster body as shown in London, complete with a three-part grille that anticipated later Aston Martin design language. One notable styling feature was a compartment built into one front wing to house the spare wheel, an unusual arrangement for the period. One additional 2-Litre car was shipped as a bare chassis to allow a customer to commission custom coachwork.
After the introduction of the replacement DB2 in 1950 — which used the W. O. Bentley-designed Lagonda straight-six engine and featured a hardtop body — the 2-Litre Sports became retrospectively known as the DB1. Only 12 had been produced by this point; however, because the DB2 was a closed car and some customers still wanted an open-top variant, chassis numbers 13, 14, and 15 were subsequently built to special order, bringing the total to 15.
One specific example, a 1949 Aston Martin DB1 registered UMD123, became the subject of an unusual international story. It was sold to New Zealand in 1991, then sold on to Japan in 1994 but was stolen from the wharf before delivery, reportedly by a Japanese gangster. The car was recovered in 2007 and subsequently sold to an Australian buyer.
The 2-Litre Sports established Aston Martin's post-war identity under David Brown and introduced the DB naming convention that would define the marque for decades. Its outright victory at Spa in prototype form, even before the production body was fitted, demonstrated a genuine racing pedigree that would become central to Aston Martin's commercial and sporting identity throughout the 1950s.