The local authority prevented five attempts to swindle cash - totalling £110,000 - but was the victim of one claim.
Coun Alan Gardiner, cabinet spokesperson for core services, said: “Organised criminals sought to capitalise on a very difficult situation.
“Unfortunately the council has been the victim of one successful fraud of £25,000.
“The funds had already been received from national government so Barnsley Council has not suffered financially from this fraud.
“The details have been forwarded to the National Investigation Service who is leading the investigation into cross-border, multi-authority Covid-19 business grant frauds and it would be inappropriate to comment further until the investigation has been completed.”