The wealth manager said Smith, who also chairs the Edinburgh-based Green Investment Bank and Forth Ports, will take up his role at the start of next month.
He succeeds Karin Forseke at the helm of the trust, which last year announced a shake-up of its corporate structure and operating model in a move aimed at cutting costs by £6 million a year.
Smith, who led the commission tasked with delivering recommendations for further Scottish devolution, previously chaired Glasgow-based engineering giant Weir Group and Perth utility SSE.
He said: “Alliance Trust is an important business with a long and proud history in Scotland and around the world. I am looking forward to getting started and playing my part in delivering the changes that are necessary to return the trust to the levels of performance upon which it has earned its reputation and success.”
Alliance Trust also announced today that non-executive director Gregor Stewart will become its deputy chairman.
“The board has been working hard on implementing the plans announced on 1 October 2015, which include creating separate boards for our savings platform and investment management subsidiaries,” Stewart said.
“The board’s focus is on investment performance, on creating natural demand for our shares and on reducing the trust’s discount.’