Labrooy's appointment comes after a selection panel led by batting great Sanath Jayasuriya resigned en masse following the team's humiliating 3-0 whitewash at home to India in a recent three-match Test series.
Sri Lanka also went on to lose a five-match one-day international series and a one-off T20 game against India.
"The new selectors will begin their term with the selection of the Test squad to take on Pakistan in their tour of UAE (United Arab Emirates) commencing early next week," Sri Lanka Cricket said in a statement.
The 53-year-old Labrooy played nine Tests for Sri Lanka, taking 27 wickets at an economy rate of 3.31.
Gamini Wickremasinghe, Jeryl Woutersz, Sajith Fernando and Asanka Gurusinha are the other members of the new panel.
The Test series with Pakistan beginning September 28 will see Sri Lanka play their first ever day-and-night game.
The teams are also due to play five ODIs and three T20s, one of which is tentatively scheduled to be played in Lahore, Pakistan.
Sri Lanka are placed seventh among the 10 Test playing nations and Pakistan sixth.