The midfielder struck in the 77th minute to condemn Graham Turner’s side to a 23rd defeat of a miserable season despite a spirited showing.
Both sides had chances in the first half but Huddersfield goalkeeper Alex Smithies made a fine save when he stopped an on-target volley from Jennison Myrie-Williams and home keeper Peter Gulacsi did well to twice keep out Anthony Pilkington.
Collins made no mistake when opening the scoring, firing home his ninth of the season from close-range after Gary Roberts’ cross fell at his feet.
Pilkington went close to adding a second for Town but Gulacsi raced off his line to deny the winger.
Hereford striker Andy Williams was brought on to rescue a point for the Bulls but his late effort was turned away by Smithies.