This was by 21.1% year-on-year and is the 23rd consecutive month of revenue growth for the sector.
The total comprised mostly of slots revenue, which hit $2.50bn for the month – a rise of 15.5%.
Revenue from sports betting rose significantly, by 58.2% to $1.02bn, marking the first time revenue for the vertical exceeded $1.0bn. This comes with one state – Arizona – still to report its revenue figures for the month.
The AGA said the sports betting boost was due to the launch of two highly anticipated state markets – Ohio and Massachusetts – during the month. Ohio generated $208.9m in revenue for January, a record for a single calendar month, while Massachusetts reported GGR of $96.9m.
The Bay State has since added mobile to the legal product range, with the first digital bets placed earlier in March.
Meanwhile, Louisiana saw the second highest revenue of any state in sports betting activities, coming in at $197m.