Orrick, Smith and Dilworth leave The Whitehouse, while Smedley is leaving The Quarry to form the company. All four will be joint directors and equal partners in the venture, which is based in Soho.
Work will open in May with four suites. It has already secured a tie-in with the New York- and Los Angeles-based editing company Lost Planet for US representation.
Dilworth said: "We're interested in moving away from the corporate experience and developing a creative environment that represents our personalities."
Smedley began his career in 1998 at the OBE Partnership. His editing credits include the Honda ads "cog" and "choir".
Orrick's reel includes the Lynx "getting dressed" spot and Adidas "road to Lisbon".
Neil Smith spent three years at The Whitehouse cutting ads including Audi "bull" and Ford Fiesta "ice-hockey".
Dilworth was The Whitehouse's managing executive producer, with responsibility for personnel, production and new business.