According to the latest available information, the top 10 biggest gambling companies in terms of revenue are:
1. Flutter Entertainment
2. Las Vegas Sands Corp
3. Galaxy Entertainment Group
4. MGM Resorts International
5. Caesars Entertainment
6. Paddy Power Betfair
7. SJM Holdings
8. 888 Holdings
9. William Hill
10. Kindred Group
Please note that rankings may vary depending on the source and the timeframe considered.