Mr Pilling joined WBD in 2015 and has led the growth of the Leeds corporate practice.
In a statement, WBD, said; "In particular he has helped to develop a strong presence for the firm in the private equity sector with the firm now advising a number of the key investors that operate in the market.
"Born in Yorkshire, Simon is a well-known dealmaker in the region with almost 30 years' experience as a corporate transactional lawyer. He has significant and varied experience advising on a broad range of transactions."
"Simon's team advises many regional, national and international clients on high profile, high value transactions.
"Deals in the last few months that Simon has led include advising LDC on the creation of a new national lettings and estate agency group in a £100 million transaction to merge Lomond Capital and Linley & Simpson; advising private equity firm Nimbus on its investment into the Yorkshire manufacturing business Hawthorn Timber; and acting for Cairngorm Capital on its majority investment in Bromborough Paints."
He takes over the role of office head from real estate partner Mark Owen who held the position for nearly 10 years.
Mr Pilling said: "It is an exciting time to be doing business in Yorkshire. Last week's announcement that the Bank of England is to locate its new Northern Hub in Leeds follows closely behind the news that the city is to be the home of the new UK Infrastructure Bank. These moves clearly underline the status of West Yorkshire as the second centre for financial services outside London.
"From a wider Yorkshire perspective we have also seen the announcement regarding the prospect of a Freeport in Humber, which is excellent news for the regeneration of that area.
"I'm thrilled to take on this important office head role within the firm and look forward to working with all my colleagues to continue to build on our strong regional profile and to ensure that our business plays its part in unlocking the tremendous potential that exist for businesses across the region and beyond."