In terms of handle, consumers wagered $18.4m on sports during the month, up 72.0% from $10.7m in April last year and also 21.5% higher than $15.2m in March this year.
Looking at individual operator performances, Caesars again led the way with $635,777 revenue off a handle of $7.8m.
Gambet, which is operated by the DC Lottery and powered by Intralot, followed in second after paying out $4.6m in winnings from $5.2m in wagers, resulting in $602,646 in revenue.
BetMGM, which operates in DC in partnership with Major League Baseball franchise the Washington Nationals, was next with $127,108 in revenue and a $5.0m handle.
Grand Central Restaurant, Bar and Sportsbook, which offers sports betting in partnership with Elys Game Technology, placed fourth with $64,744 from $449,111 in bets.