Updated July 18, 2023
As far as we know, there's no agreed-upon record of the largest-ever casino tip. Toking is often a private matter and many "Georges," the gambling term for big tippers, don't want the size of their tips spread around.
That said, the largest known tokes in the modern history of casino gambling are attributed to Kerry Packer, before his death the richest Australian. Here are a few examples.
Packer was playing baccarat at the Mirage shortly after it opened in 1989 when he made a $100,000 bet for the dealers. The bet won.
One time in the mid-‘90s when he won $26 million at the MGM Grand, he tipped each dealer on duty $2,500, which added up to $105,000.
Once, after accidentally bumping a cocktail waitress and causing her to drop her tray of drinks, he asked for her name and address. The next thing she knew, her $130,000 mortgage had been paid off.
While playing blackjack at the Las Vegas Hilton in the ‘90s, he took a liking to Kristine W of The Sting, the house band in the Hilton’s Nightclub at the time. On a break, she came out and sat with Packer at the blackjack table, where he made a $50,000 bet for her. The hand won and Kristine was $100K richer. In the same round on a different hand, he made a $50,000 bet for the dealer, but that hand lost.
Another famed big tipper of recent times is Hollywood actor Ben Affleck, who twice allegedly distributed tips of about $150,000 after winning big at the Hard Rock. However, during their first engagement (they had two and suceeded in getting married the second time), Jennifer Lopez (a.k.a. J-Lo) apparently clamped down on her Affleck's legendary toking habits, earning her the nickname in Vegas of "Pay Low." According to a published report in 2002, during their Thanksgiving holiday visit to Vegas that year, the couple was playing baccarat at the Mirage and Affleck tossed a $5,000 white chip to the dealers, only to have J.Lo pronounce "No," retrieve the chip, and exchange it for three black $100s.