Commercial litigation partner Roger Brown joins from Stephenson Harwood, where he was a partner for 21 years.
He says he felt like a move and wanted to go to "the best litigation practice in the City."
Herbert Smith has also poached a US law professional support lawyer from the London office of Brown & Wood. Associate Kathleen Brennan de Jesus has also practised US securities at Jones, Day, Reavis & Pogue.
Jim Wickenden, a US-qualified partner practising in Herbert Smith's London office, said: "Her arrival and the establishment of a dedicated US know-how source will provide us with a first class resource for our growing US law capability."