Sadly, there are very few online American Express Sportsbooks. Due to American Express' diligence to remaining uninvolved with online gambling, they have not become a very viable payment solution for sports betting enthusiasts. Currently, there is only one online sports book known to have any margin of success with American Express deposits, but it does have a great processor that usually gets the deposits approved.
As we anticipate the legalization of online gambling for US players, we are also hopeful that US banks and credit card companies will respond to the reversal of the financial restrictions and will begin processing transactions which are tied to online gaming. Once this occurs, we expect to see more Sportsbooks Accepting American Express begin to surface throughout the online gaming industry. Until that time, it's a hit or miss option that may end up being a little more trouble than its worth.