March 1922: Superior Judge J.R. Welch of San Jose, CA ruled that George Jones had to pay Henry B. Stuart a grand total of $304,840,332,912,684.16.
The reason was that in 1897 Stuart had loaned Jones $100, and the two had signed a contract agreeing that the debt would grow by 10% a month, compounded, until paid back.
Jones had then left the state and forgotten about the debt. But Stuart hadn't forgotten, and when Jones returned a quarter century later, Stuart sued him. The judge agreed that the debt was still owed, and by the terms of the original agreement had grown to over $300 trillion.
Of course, Jones promptly declared bankruptcy. But I'm pretty sure the ruling remains the highest court judgment in history. Though because it was essentially a meaningless judgment, it's typically overlooked. For instance, Google AI says that the largest court judgment ever was the
$206 billion Tobacco Master Settlement Agreement.

Jackson Citizen Patriot - Mar 27, 1922

San Francisco Examiner - Mar 2, 1922
Category: Money | Outrageous Excess | World Records | Lawsuits | 1920s