Yes. Kalshi operates fully in California, sports contracts included, and so do Polymarket US and Novig. California has never legalised sports betting (voters rejected two measures in 2022), which makes it the largest market in the country where a prediction market is the only regulated way to trade on a game. That's also why three California tribes sued under federal gaming law. A federal judge denied their request to block the markets; they've appealed to the Ninth Circuit, the same court that ruled against Kalshi in Nevada in August 2026. Status as of October 15, 2026.
What's available
| Platform | Status in California | Age |
|---|---|---|
| Kalshi | All markets, including sports and combos | 18 |
| Polymarket US | Available via the app | 18 |
| Novig | Available (not one of its three excluded states) | 21 |
| Robinhood / DraftKings / FanDuel prediction products | Available | 18 |
The legal picture
Unlike Nevada, Michigan or Massachusetts, the State of California has not sued Kalshi or sent a cease-and-desist. The challenge comes from tribes. In July 2025 three tribes sued, arguing that sports prediction markets violate the Indian Gaming Regulatory Act and the exclusivity California's tribal compacts grant over gaming. A federal district judge denied a preliminary injunction, and the tribes appealed to the Ninth Circuit.
That appeal matters more after August 28, 2026, when a Ninth Circuit panel ruled in Nevada's case that Kalshi's sports contracts are likely sports gambling under state law rather than federally protected swaps. The California case turns on different law (IGRA rather than Nevada's gaming statute), but it's the same circuit, and a win for the tribes could reach sports contracts across the state.
Why California is the big one
Forty million people, no sportsbooks, and a state legislature that has not moved on sports betting since the 2022 ballot defeats. Prediction markets stepped into that gap in 2025, and the volume reflects it. For users that means deep markets on California teams; for the platforms it means the tribal appeal is the most commercially important case they have outside the Supreme Court.
What to do
- You can sign up and trade on all three platforms today.
- If the Ninth Circuit rules for the tribes, expect sports boards to be geofenced in California the way they were in Nevada, with open positions settled per the platform's notice. Non-sports markets wouldn't be affected.
- Check this page's date; we update it when the ruling lands.
Sources: district court order denying the tribes' injunction and Ninth Circuit docket, as reported by CBS Sports (Oct 13, 2026) and OddsShopper (Oct 15, 2026); platform availability pages.