Reynolds Smith, who will join Smiths on 25 September 2015, is currently chief executive of GKN Automotive.
Philip Bowman, who is retiring, will continue as chief executive of Smiths until he hands over to Reynolds Smith.
Sir George Buckley, chairman of Smiths, said: “I am absolutely delighted that we have attracted someone of Andrew’s calibre as our new chief executive. Andrew has almost 20 years’ experience running large, complex global industrial engineering operations with a track record of delivering turnarounds and above market growth rates. His career has equipped him to grow businesses through innovation and technical excellence as well as through targeted M&A. Smiths will greatly benefit from his engineering insight and leadership skills."