Eoghan O'Lionaird will join James Fisher and Sons as chief executive on 1 October, following Nick Henry's decision to step down from the position after 15 years.
O'Lionaird will join the London-listed company's board at the start of September.
The company said Henry, who resigned last December, will remain employed by the marine services company until 31 March 2020, "to ensure a smooth and effective transition of responsibility".
O'Lionaird joins from Spectris, a supplier of precision instrumentation and controls and a FTSE 250 company, where he has been divisional chief executive and a member of the executive committee.
"Eoghan has gained significant business experience in growing decentralised businesses both through organic and acquisitive strategies," Malcolm Paul, chairman of James Fisher, said.
"A strong motivational and results-driven leader, Eoghan has a history of creating highly engaged teams, which suits the James Fisher culture, and with excellent international business experience, he has the drive to help take the group to the next level."
Before O'Lionaird joined Spectris, he held senior management roles at Danaher Corp and Royal Philips Electronics.
This year has seen James Fisher renew its fleet of small tankers and buy two subsea support ships.
