The hatchback and cabriolet versions have been complimented by a huge range of special editions including the recently introduced Fiat 500 Pink in two different body styles.
The multi-award winning small car reached the landmark when a 1.2-litre version in Funk White finished was completed recently.
Fiat employees gathered to celebrate the achievement, which has been reached in just 21 months since the model was launched in 2007.
Manufactured in Poland, the Fiat 500 enjoys its greatest sales in Italy, where 244,755 units have so far been sold.
France and the UK are second and third respectively with over 50,000 sales each. The only non-European country in the top ten is Japan, with 9000 sales.
Fiat says 80 per cent of sales are for top range Lounge and Sport versions, although Pop and byDiesel models are also available.
However, the Fiat has some way to go before it catches one of the most produced cars ever – the Ford Model T, which sold over 16,500,000 models worldwide.