First-half strikes from Sean Morrison, Hoilett and Rickie Lambert ensured it was another away day for the Terriers to forget.
Huddersfield were thumped at Fulham in their last away game before the international break and did not fare any better at the Cardiff City Stadium.
Tommy Smith pulled a goal back for Huddersfield at 2-0, while Phil Billing's wonder-strike made it a nervy ending for Cardiff.
But they held on, meaning the Terriers have won just once in their last six games, slipping to fourth in the Championship.
Huddersfield's Nahki Wells had the first real chance of the game and should have done better when Kasey Palmer played him in on goal, but the striker's shot was too tame to trouble Cardiff goalkeeper Ben Amos.
Cardiff took the lead in the 15th minute through their skipper Morrison who connected with Peter Whittingham's corner to head past Danny Ward.
Neil Warnock's men doubled their goal advantage just two minutes later after Ward spilled Anthony Pilkington's shot, and it fell to Hoilett who slotted home.
It was the Canada international's first goal for the club since arriving on a free transfer last month.
Huddersfield pulled one back through Smith after Palmer's clever through ball found the skipper who smashed the ball past Ben Amos.
But the Bluebirds restored their two-goal advantage just five minutes later as the Terriers failed to deal with another set-piece.
Whittingham's pumped ball into the box was headed on by Morrison and volleyed in by Lambert, who was making his first home start since recovering from injury.
Cardiff could have gone into the break 4-1 up, but Whittingham was just inches away from connecting with Lambert's chipped cross.
Substitute Billing's half-volley from 20 yards out made it a nail-biting final 20 minutes for Cardiff boss Neil Warnock, who had a spell managing the West Yorkshire side in the mid-1990s.
The goal breathed new life into the visitors as Wells did well to hold the ball up, and his cross was agonisingly close to reaching the onrushing Sean Scannell.
Huddersfield kept on pushing for the equaliser when Scanell's cross was brilliantly headed away by Sol Bamba.
Despite going 16 games without a clean sheet for the first time sine 1989, Bamba and Morrison defended their box valiantly in the closing stages of the contest.
Cardiff: Amos, Peltier, Bennett, Bamba, Morrison, Whittingham, Ralls, Gunnarsson, Pilkington, Hoilett, Lambert
Subs: Wilson, Connolly, Richardson (Hoilett, 89), Harris, Chamakh, Noone, Gounongbe (Lambert, 75)
Huddersfield: Ward, Smith, Stankovic, Hefele, Schindler, Lowe, Mooy, Hogg, Palmer, Wells, Kachunga
Subs: Coleman, Whitehead, Hudson, Scannell (Schindler, 61), Billing, (Hogg, 61) Holmes-Dennis, Van La Parra
Bookings: Peltier (47) Mooy (49) Hogg (49) Bamba (72) Hefele (72)