Development of the Leopard 1 can be traced back to November 1956, when the operational requirement for a new battle tank was formulated by the Federal German Armed FOrces (Bundeswehr). The first tank operated by the Bundeswehre were the US-built M47 and M48, wich were cheap and available in quantity. The M47 in particular was very much an interim design. With the M47 virtually obsolete, the Bundeswehr badly needed a thoroughly modern main battle tank (MBT), with the armor and firepower to take on the vastly superior numbers of excellent MBTs operated by the Soviets.

In 1957, the Bundeswehr's specified their new MBT. It should have sufficient armor to withstand hits from 20 mm rounds at close range. The main gun should be capable of penetrating 150 mm of sloped armor, while the ammunition load should at least be equal to that of current US tanks.

In June 1957 Germany and France signed a co-operation agreement to develop a common tank, designated "Standard-Panzer". Two German and one French design team would be responsible for the construction of four German and two French prototypes of the vehicle. In September 1958 Italy joined the development programme.

Between August-October 1963 comparitive trials were conducted between the German and French designed prototypes in France and Germany - interestingly, all under Italian supervision. The trial demonstrated that the German tank had the edge over the French MBT. But intriguingly a change in defence policy, together with funding problems, suddenly prevented the French from purchasing any new tanks before 1965. This ended the Franco-German effort to produce a common MBT. The French Army received the French version of the trials, know as AMX-30 in 1966. The Italians decided to be different and purchased the American M60A1 instead (The bought the Leopard later). Germany commenced series production of the Leopard in 1966.

The MBT was officially named Leopard in 1963. This was an appropriate choice considering Germany's wartime pedigree with the formidable Tiger and Panther.

On 22 August 1963, an order for 1,500 Leopards was placed for the Bundeswehr. The first series production Leopard left the newly built assembly line of prime contractor Krauss-Maffei AG in Munich on 9 September 1965. The Leopard 1 was built in six batches (or "lots"), a small number also being built by Krupp MaK in Kiel.