Is Polymarket legal in South Dakota?
South Dakota at a glance
| Question | Position as of 22 October 2026 |
|---|---|
| Does Polymarket US accept South Dakota users? | Yes, with no state-specific restriction reported; identity verification and US-dollar deposits required, minimum age 18 |
| Can South Dakota residents use polymarket.com? | No; the offshore site geoblocks the United States under the January 2022 CFTC order |
| Has South Dakota sent Polymarket a cease-and-desist? | No publicly reported letter |
| Has South Dakota sued Polymarket? | No |
| Is South Dakota on record against event contracts? | As a signatory: the 41-AG CFTC comment letter (April 30, 2026) and the 39-state Supreme Court amicus brief in No. 26-299 (October 7, 2026) |
| Legal sportsbooks | Retail only, in Deadwood and at tribal casinos under compact; bettors 21 and over; no online sportsbook |
| Pending legislation | None; SJR 504 died in House State Affairs on February 25, 2026; the legislature returns in January 2027 |
| Federal circuit | Eighth Circuit; no appellate ruling; Minnesota ban enjoined at district court on July 27, 2026 |
| Kalshi's position in South Dakota | The same: available, no state action; see Is Kalshi legal in South Dakota? |
Which Polymarket a South Dakotan can use
There are two Polymarkets. The original site, polymarket.com, settles in the USDC stablecoin and has been barred from serving US persons since the CFTC's January 3, 2022 order against its operator, which carried a $1.4 million penalty. Reaching it through a VPN from Sioux Falls breaches that order and the site's own terms. The product built for Americans is Polymarket US, which runs on QCX LLC, a designated contract market the CFTC approved on July 9, 2025 and which the Commission's filings list as "now operating under the assumed name of Polymarket US." It takes dollars, verifies identity, checks location at sign-up and accepts users from 18, three years younger than a Deadwood sportsbook allows. The federal licence and the national picture are covered in Is Polymarket legal in the US?; CBS Sports' state guide, updated October 21, lists South Dakota as live for sports contracts.
A sportsbook industry you have to drive to
South Dakota's gambling law is built around one town. Constitutional Amendment B, approved by 58.5 percent of voters in November 2020, allowed sports wagering within Deadwood's city limits, and tribal compacts extend the same right to tribal casinos. There is no statewide app and no remote registration. The Deadwood Gaming Association told KELO in September 2026 that the town's seven sportsbook locations had taken more than $41 million in wagers in five years.
The 2026 attempt to change that came closer than any before it. SJR 504, a constitutional amendment for mobile betting routed through Deadwood servers, passed the Senate 23 to 10 on February 11. On February 25 the House State Affairs Committee voted 7 to 6 against advancing it and then deferred it past the end of the session. There is no sports betting question on the November 3, 2026 ballot. Deadwood's operators argued for the amendment partly by pointing at prediction markets, which reach 18-to-20-year-olds that a Deadwood book cannot serve. That complaint has produced cease-and-desist letters in Ohio and Missouri. In South Dakota it has produced a lobbying position.
What the attorney general has signed, and what he has not sent
Marty Jackley's office has joined the multistate documents. The April 30 comment letter argued that "any distinction between sportsbook bets and prediction-market bets is illusory," and the October 7 amicus brief, filed by Ohio's solicitor general for 39 states and the District of Columbia in Flaherty v. KalshiEX, asks the Supreme Court to take New Jersey's case. Both name the practice, not Polymarket specifically. What the office has not done is act alone: no letter to Polymarket US or anyone else, no civil suit, no criminal referral. The South Dakota Commission on Gaming oversees Deadwood licensing and compact compliance and has not asserted jurisdiction over event contracts. Ohio, by contrast, put Polymarket on its list of ten recipients on October 2, and Polymarket US sued Ohio on October 16; nothing like that sequence has started in Pierre.
The Eighth Circuit and the federal question
South Dakota's appeals court is the Eighth Circuit, shared with Minnesota, North Dakota, Iowa, Nebraska, Missouri and Arkansas. It has not decided whether sports event contracts are swaps or whether federal law preempts state gambling law. The only ruling in the circuit is Judge Katherine Menendez's July 27, 2026 order in the District of Minnesota enjoining that state's felony ban, on the finding that the United States, Kalshi and Polymarket US were likely to succeed on preemption. Two more cases arrived on October 16, when Novig and Crypto.com's OG.com exchange sued Missouri officials in the Eastern and Western Districts of Missouri; appeals from either go to St. Louis.
Elsewhere the courts are split. The Third Circuit ruled for Kalshi in New Jersey in April; the Ninth ruled for Nevada in August, and the Sixth for Ohio and Tennessee on September 25. New Jersey's Supreme Court petition is pending, with Kalshi's response due November 9, and the CFTC's proposed rule writing event contracts into the swap definition is open for comment until November 18. A Supreme Court decision would bind South Dakota along with every other state. Polymarket US is not a party to that case, but the question it answers is the same one.
How Polymarket compares with Kalshi in South Dakota
In practice the two are in the same position: available, unlicensed by the state, not paying Deadwood's 9 percent gaming tax, and untouched by state enforcement. The differences are in the products. Polymarket US is the younger federal exchange, and the two charge different fees, which our fee comparison sets out. Legally, the only distinction that has mattered elsewhere is who a state chose to name; South Dakota has named neither.
What this means in practice
For a South Dakota resident, the Polymarket US app works and the state has not tried to stop it. The things that could change that are, in order of likelihood, an Eighth Circuit ruling arising from the Missouri or Minnesota cases, a Supreme Court decision in New Jersey's case, or a change of course in the attorney general's office. The legislature does not meet again until January 2027. This is a description of current enforcement, not a legal opinion on whether trading is lawful.
Frequently asked questions
Is Polymarket legal in South Dakota?
Polymarket US, the CFTC-regulated exchange, is available in South Dakota and the state has taken no action against it: no cease-and-desist letter and no lawsuit as of October 22, 2026. South Dakota has signed multistate documents arguing sports event contracts are gambling, but has not acted on its own. That is the enforcement position, not a court ruling.
Can I bet on sports online in South Dakota?
Not with a sportsbook. Sports wagering is legal only in person in Deadwood and at tribal casinos, for bettors 21 and over. The 2026 online amendment, SJR 504, died in a House committee on February 25, 2026.
Can I use polymarket.com from South Dakota?
No. The offshore site has been closed to US persons since the CFTC's January 2022 order and geoblocks the United States. The product available to residents is the Polymarket US app.
Which court decides Polymarket's status in South Dakota?
The Eighth Circuit, which has not ruled. The only decision inside the circuit, a July 27, 2026 injunction against Minnesota's ban, favoured the exchanges, including Polymarket US. A Supreme Court ruling in New Jersey's case against Kalshi would apply nationwide.
Related
- Is Kalshi legal in South Dakota? No letter, no suit
- Is Polymarket legal in the US? Two Polymarkets, one federal licence
- Is Polymarket legal in Idaho?
- Is Kalshi legal in your state? The 50-state tracker
- Odds converter: cent prices, American odds and the vig
Sources
- Maryland Office of the Attorney General, Multistate comment letter to the CFTC, 30 April 2026, for South Dakota's signature and the quotation.
- Supreme Court of the United States, Brief of Ohio and 38 other states and the District of Columbia, No. 26-299, 7 October 2026.
- iGaming Business, Online South Dakota sports betting bill stopped, February 2026, for the House committee votes on SJR 504.
- Yahoo Sports / KELO, Deadwood sports betting tops $41 million, September 2026, for the handle and location figures.
- Courthouse News, Order enjoining Minnesota's prediction market ban, 27 July 2026.
- Covers, Novig, Crypto.com sue Missouri after cease-and-desist order, 16 October 2026.
- CFTC, Designated contract market filings: QCX LLC d/b/a Polymarket US, for the July 9, 2025 designation; and the January 3, 2022 order.
- CBS Sports, Are sports prediction markets legal? Status of Kalshi and Polymarket in all 50 states, 21 October 2026, for availability; a third-party guide, not a venue statement.
18+ only. Prediction market contracts carry real financial risk. This page is analysis, not legal, financial or betting advice. If gambling stops being fun, help is available at 1-800-GAMBLER.