The A-bike is a folding bicycle invented by Sir Clive Sinclair in the United Kingdom and released on 12 July 2006. It weighs 5.5 kilograms (12 lb) and folds to 67×30×16 centimetres (26.4×11.8×6.3 in), small enough to fit in a rucksack.

The A-bike was designed by a team at Daka International Ltd, in Hong Kong, and Sinclair Research over 5 years. It was announced to the public in 2004. Clive Sinclair envisioned the A-bike, and Alex Kalogroulis was the main design engineer.