Andre Boisclair will be the province's delegate-general to New York City. Boisclair, 46, enters his new role next week.
He served in several cabinet positions under the last PQ government after having been elected for the first time at age 23.
But his leadership stint was marred by electoral disappointment, with the party plunging to third place in 2007 in its worst result since it was a fledgling political outfit in the early 1970s.
The onetime environment minister went on to a consulting career where clients included members of the shale-gas industry — a controversial sector in Quebec.
While other provinces have international agents, Quebec has a larger foreign presence than others and has its own international-relations department.
He replaces John Parisella, a former senior provincial official who was the representative of the previous Quebec Liberal government.