No, it's not. Although more than 30 states have now legalized online sports betting or casino games in some form, all types of online gambling are illegal in California. As things stand, you cannot legally place an online bet on a sports event, and you cannot play casino games on your desktop or your mobile device.
You will find some social casinos on the App Store or Google Play Store that won't pay real money, but you can win real money on slot apps that we have recommended.