The borough’s rate stood at 548.9 per 100,000 people last week, but the latest figures show it’s dropped to 502.7 per 100,000.
Only Sheffield now has a lower rate in South Yorkshire, as Doncaster and Rotherham’s seven-day rates have soared to 568.1 per 100,000 and 521.1 per 100,000 respectively.
However, rates are still much higher than the national average, which is currently 228.1 per 100,000.
Barnsley Council’s director of public health Julia Burrows said it was important people continued to work together to protect vulnerable people in the borough.
“Everywhere you go socially, at work or school, act as if everyone you meet could be infected so you do everything you can to protect yourself and others,” she said.
“And remember, the more mixing you do, the more likely you are to become infected and to infect others.”