Best Online Sportsbook Colorado: DraftKings Leads a Crowded Field

Best online sportsbook Colorado is a wider field than most states offer, with 25-plus licensed mobile apps competing for the same bettors. DraftKings has led the pack in handle every single month since the market opened, but the more interesting story is the rule almost nobody who places a bet here actually knows about: none of those apps holds its own Colorado license. Every one of them is sponsored by a small casino most bettors have never set foot in.

A Razor-Thin Yes, Then a Fast Launch

Proposition DD passed on November 5, 2019, by 50.7% to 49.3% — roughly 11,000 votes out of 1.4 million cast, one of the closest statewide results in Colorado that year. It authorized a 10% tax on casinos' net sports wagering proceeds, with the money earmarked for the Colorado Water Plan rather than the general fund. The market moved fast once it passed: mobile sports betting went live on May 1, 2020, regulated by the Colorado Division of Gaming under the Limited Gaming Control Commission.

Why Every App Has a Mountain Casino Behind It

Colorado never created a standalone online sportsbook license. Instead, only land-based casinos physically located in Black Hawk, Central City, or Cripple Creek can hold a sports betting master license, and state rules let each master licensee contract with up to one retail sportsbook operator and one internet sportsbook operator at a time. Monarch Casino and Saratoga Casino in Black Hawk, Double Eagle Hotel and Casino and others in Cripple Creek, and Dostal Alley in Central City are the kind of small operators quietly sponsoring the national brands bettors actually download.

DraftKings Leads, But the Gap Is Shrinking

DraftKings has held the largest share of Colorado handle every month since the May 2020 launch — a streak that predates most of its current competition. FanDuel, the national market-share leader at 38% to DraftKings' 34%, has run neck-and-neck with it in Colorado since the same opening week. The more recent development is bet365 and Fanatics: both have spent the better part of 2026 pushing aggressive odds boosts and sign-up offers that have started registering in Colorado market-share tracking against the two established leaders.

The Tax Break That's Disappearing in 2026

House Bill 1311, signed May 15, 2025, phases out the deduction sportsbooks could claim for promotional and free bets when reporting taxable revenue — a cap that had already stepped down from 2.25% to 2% in mid-2025 and 1.75% through 2026, and disappears completely on July 1, 2026. Separately, voters passed Proposition JJ in November 2024 with 76.44% support, eliminating the $29 million annual cap on how much sports betting tax revenue the state could keep. Together, the two changes mean more of every taxed dollar now reaches Colorado's water projects than at any point since 2020.

A newer law reaches the bettor side directly: Senate Bill 26-131, the Sports Betting Protections Act, took effect August 12, 2026. It bans credit card deposits on Colorado sportsbook apps, limits any account to six deposits a day, and bars operators from texting or push-notifying someone to deposit or place a bet. None of this is a way to make money — it's 21+ entertainment with a real house edge, and it now comes with more consumer guardrails than Colorado had when the market opened in 2020.

The short list

1. 1. DraftKings — Handle leader in Colorado every month since launch

   DraftKings has held the largest share of Colorado sports betting handle every month since the market opened on May 2020, the day after Proposition DD passed by a 50.7%-to-49.3% margin — about 11,000 votes out of 1.4 million cast. Its Colorado license runs through a master-licensed casino in the Black Hawk/Cripple Creek/Central City system, the same structure every operator on this list uses.

2. 2. FanDuel — The national handle leader (38% share), live in Colorado since week one

   FanDuel holds the largest nationwide sportsbook market share (38%, versus DraftKings' 34%) and has operated in Colorado continuously since the May 2020 launch. It's the closest thing to a toss-up with DraftKings for a reader who cares more about app polish and prop variety than a specific handle edge in this state.

3. 3. bet365 — Global operator gaining Colorado share through 2026

   bet365 built its business in the UK before ever touching a US market, and through 2026 it has been one of two apps (alongside Fanatics) visibly chipping into DraftKings' and FanDuel's combined Colorado lead with aggressive early-market odds boosts. It's a newer account here than the two leaders, not an unproven one.

4. 4. Fanatics Sportsbook — The other app taking share from the two leaders in 2026

   Fanatics Sportsbook leveraged its existing merchandise-site user base to push into Colorado with sign-up offers aggressive enough to register in 2026 market-share tracking against DraftKings and FanDuel. It's the newest major name on this list and still building its in-state track record.

5. 5. BetMGM — Best pick for a combined sportsbook-and-casino-style account

   BetMGM runs a full sportsbook in Colorado under the same master-license model as the rest of this list, paired with the deepest MGM-branded parlay and same-game-parlay tooling of the five. A solid default for a reader who wants one login rather than the sharpest line.

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