Padbury was born at Stonesfield, near Woodstock, in the English county of Oxfordshire. He arrived in Fremantle, Western Australia in the Protector with his father on 25 February 1830, but in the following July his father died. The lad was left in the care of a married couple who stole the money his father had left and absconded. Padbury then had to fend for himself. He followed various occupations and when 16 was shepherding near York for £10 a year. Later he saved enough to send for his mother and the rest of his family, took up land, was one of the first settlers to open up the north-west of Australia, and in 1863 was sending stock by sailing ships to Carnarvon.
He retained his interest in the north-west all his life, but he also established a general store business in Perth and other centres. Late in life he founded a successful flour-mill at Guildford. He was much interested in the Royal Agricultural Society of Western Australia and was president in 1874, 1875, 1876 and 1885.
For many years he was a member of the Perth city council, for some time was chairman of the Guildford council (now the Swan), and for five years was an elected member of the Western Australian Legislative Council. He travelled in Europe and the United States of America, and at one time thought of settling in England again, but found the climate did not suit him. He died at Perth on 18 April 1907. His wife, Charlotte, had died in February 1895.
Padbury was a good example of the kind of man who, having no advantages and no one to help him, rises to a leading place in his community. Having got into a good financial position he not only helped his own family, he held out a helping hand to many other men less fortunate than himself. He was a generous contributor to charitable institutions and was particularly interested in orphan children. A sincerely religious man he gave largely to his church, and it was principally due to his munificence that it was found possible to establish the Anglican Diocese of Bunbury. By his will large sums of money were left to various Western Australian charitable institutions.
Walter Padbury was well known for his charitable works. He sponsored an eye operation for a sandalwood farmer named Edmund Keen Byrne (1833–1904) of Bindoon. Edmund had originally arrived in Perth on the ship Orient in 1848 as a Parkhurst Lad. Walter not only paid for his trip to London in 1878 on his ship the Charlotte Padbury, but also paid for the operation (necessary because of 'Sandy Blight') and accommodation etc. whilst in London, a period of nearly six months.