Roach, who celebrates his 20th birthday later this month, is the only surprise in the 14-member squad, and is one of the two changes for the Test, starting on Thursday at Kensington Oval.
Roach and left-handed opener Sewnarine Chattergoon replace Brenton Parchment and Devon Smith in the squad which had been selected for the second Test in Antigua.
West Indies expect the Kensington Oval pitch to offer plenty more pace and bounce than the pitches in the two previous Tests, and have brought Roach in to bolster their attack, as well as cover for the other main fast bowlers - all of whom have niggling injuries.
Roach was a member of the Young West Indies side that appeared at the Youth World Cup two years ago in Sri Lanka.
He is a highly-regarded, young fast bowler, and made his first-class debut for Barbados in January. He appeared in four matches capturing seven wickets at 30.57 apiece.
Chattergoon would have been a virtual certainty for the series had a shoulder injury not sideline him for the first two Tests.
The 27-year-old Chattergoon was called into the West Indies side after showing consistent form for his native Guyana and West Indies-A.
He made his long-awaited Test debut against Sri Lanka in March, and looked solid enough with scores of 46 and 11.
Chattergoon and West Indies captain Chris Gayle, who is also expected to make his return from injury for the Test, should give the home team a more stable opening partnership, since Parchment, Smith, and Xavier Marshall - to a lesser extent - all struggled to cope.
West Indies trail in the three-Test series 0-1, after they lost by 95 runs in the opening Test at Sabina Park in Kingston, Jamaica.
Australia have already retained their hold on the Frank Worrell Trophy - symbol of Test supremacy between the two sides - and have not lost a Test series in the Caribbean since 1991.
West Indies squad: Chris Gayle (captain), Ramnaresh Sarwan (vice captain), Sulieman Benn, Dwayne Bravo, Shivnarine Chanderpaul, Sewnarine Chattergoon, Fidel Edwards, Xavier Marshall, Runako Morton, Daren Powell, Denesh Ramdin, Kemar Roach, Darren Sammy, Jerome Taylor.