The 2021 season of the Knock on Effect New South Wales Cup was curtailed due to lockdowns introduced to combat the Delta variant of the COVID-19 pandemic in New South Wales.
The table below reflects the competition ladder at the completion of Round 15.
[2] This was the last completed round played, and occurred on the weekend of 19–20 June 2021.
During July and early August 2021, when there was a hope that the competition could be resumed in late August and September, scheduled matches were cancelled, with the result recorded as a nil-all draw.
A Round 2 match between Blacktown Workers Sea Eagles and South Sydney Rabbitohs was postponed due to wet weather.