The siege of Basing House near Basingstoke in Hampshire, was a Parliamentarian victory late in the First English Civil War. Whereas the title of the event may suggest a single siege, there were in fact three major engagements. John Paulet, 5th Marquess of Winchester owned the House and as a committed Royalist garrisoned it in support of King Charles I, as it commanded the road from London to the west through Salisbury.

Hampshire is a ceremonial county in South East England. It is bordered by Berkshire to the north, Surrey and West Sussex to the east, the Isle of Wight across the Solent to the south, Dorset to the west, and Wiltshire to the north-west. The cities of Portsmouth and Southampton are the largest settlements and the county town is the city of Winchester.