The axe was wielded with just one game of the regular season remaining, with a place in the League One play-offs up for grabs when Northampton Town visit Oakwell.
Martin Devaney, a member of the Reds coaching staff, has been handed the reins on a temporary basis and is currently preparing the Reds to face the Cobblers.
However, it remains to be seen how long he will be at the helm for. He has emerged as the early favourite for the role, marginally ahead of his former colleague Michael Duff.
Fortunately for Barnsley, there is a raft of experienced coaches currently out of work and available on the market. From up-and-coming managers to seasoned veterans of the dugout, there is plenty of variety.
If Barnsley do go down the route of looking at unemployed managers, here are 21 figures they could turn to in their hunt for a Collins successor.
1. Neil Warnock
The veteran manager stepped down as interim manager of Aberdeen in March. A promotion expert, he has previously indicated a willingness to take on short-term roles. He may have said he is retired - but he has said it before and still returned to the dugout. Photo: Matt McNulty/Getty Images
2. Paul Heckingbottom
The former Barnsley boss has not returned to the dugout since he was dismissed by Sheffield United in December. Photo: Nathan Stirk/Getty Images
3. Michael Duff
Duff left Barnsley for Swansea City last summer but his time in Wales proved short-lived. Photo: Ryan Hiscott/Getty Images
4. Gareth Ainsworth
Ainsworth was relieved of his duties as QPR boss earlier on in the campaign. Photo: Clive Rose/Getty Images