Wilder was a firm of ironfounders and agricultural engineers from Wallingford in Berkshire. They rebuilt a number of steam engines along with other agricultural machinery, as well as building new machinery. The company has had several names as it passed down the generations from the early 1800s onward.
Old Berkshire trade directories show Leonard Wilder established as an ironfounder and plough manufacturer at Mill bridge, Wallingford, by 1830.
- 1847 - succeeded by Richard Wilder, ironfounder, in Fish Street, Wallingford, remaining under that name until 1868.
- 1869 - the firm is listed as Wilder Brothers.
- 1876 - expansion had produced R.J. and H. Wilder [the partners being Richard, James and Henry Wilder] engineers, iron and brass founders, millwrights, and manufacturers of agricultural implements and machines, located at Wallingford iron works.
- 1883 they also had established an office in St Mary's Street.
- By the 1890s expansion resulted in a firm which was described in 1895 as being "engineers, ironfounders, implement manufacturers, & steam plough & threshing machine proprietors. They had also become coke, coal and salt merchants, based at the St Mary's Street Office. Between 1903 and 1911 they dropped this last branch, and began to manufacture various types of carts and wagon, and in 1909 began as motor engineers.
- Between 1928 and 1931 the firm resumed activity as a coal merchant.
- Some time between 1935 and 1939 the firm was renamed John Wilder Ltd, and had also become electrical engineers, having merged with John Wilder of Reading. (This firm is first recorded in 1869 as James Wilder & Sons, at the Yield Hall Foundry in Minster Street, although in the early 1930s it moved to The Cattle Market.)
There is a firm of Lister Wilder who trade as agricultural engineers still in the area today.
Business records of R.J. & H. Wilder (later John Wilder Ltd), agricultural engineers of Wallingford, 1859-1949, 1964 held by the local archives and the MERL project at Reading.