England has already lost the series 2-0, but finally dug in against a bowling attack minus captain Jason Holder, who has been banned from the test for his team's slow over-rate in the three-day second test in Antigua.
Ironically, Holder's replacement, Keemo Paul, removed both openers and was the only bowler with two wickets.
Stokes, whose availability was in some doubt because of a bruised right heel, was a fortunate 62 not out, and Buttler was 67 not out. Their unbeaten partnership of 124 started in the middle session and handled three overs of the new ball.
West Indies stand-in captain Kraigg Brathwaite made England bat, and they broke the opening stand in the 17th over when Keaton Jennings guided Paul to the slips after taking 42 balls for 8.
Paul then bagged Rory Burns lbw on middle stump, after the opener scored 29 off 103 balls.
Joe Denly, playing his second test, made 20 off 50 balls before he was lbw to Shannon Gabriel.
When captain Joe Root nicked one behind on 15 from 54 balls, he was out to Alzarri Joseph for a third straight time.
Joseph also dismissed Stokes caught and bowled on 52 in the 70th over, but long after Stokes left the pitch he was summoned back when video showed Joseph no-balled.
After all the balls absorbed in the first half of the day, Stokes and Buttler handled the tiring West Indies attack with little other bother.
Stokes reached his 17th test half-century, and first on this tour. He has six boundaries.
After given life by the no ball, he helped England pass 200 and Buttler reached his 13th half-century in the same over. He's hit nine boundaries.