Biggest Online Gambling Sites 2024

Ever wondered which online casinos stand out as the industry's giants? The largest online casino in the world is open to debate. With thousands of places to spin the wheel and fortunes at our fingertips, we’re truly spoiled for choice. 

Mr. Gamble's experts have delved deep, testing and reviewing the biggest casinos to ensure your gaming choices are backed by genuine insights. Unlock a world of grand-scale excitement, supported by reviews that prioritize your ultimate gaming experience.

On this page you'll not only find the biggest casinos but also some of the biggest online gambling sites that have great offers to take up today. We’ve had a look at some of the world's top online casinos and here are just a few of the best for you:

  1. 1
    100% / € 3001st Deposit Bonus
  2. 2
    100% / € 2001st Deposit Bonus
  3. 3
    100% / € 5001st Deposit Bonus
  4. 4
    100% / USDT 2501st Deposit Bonus
  5. 5
    100% / € 3501st Deposit Bonus
  6. 6
    100% / € 4001st Deposit Bonus
  7. 7
    100% / € 5001st Deposit Bonus
  8. 8
    100% / € 3001st Deposit Bonus
  9. 9
    100% / € 3001st Deposit Bonus
  10. 10
    100% / $7501st Deposit Bonus

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Our editorial policy includes fact-checking all casino information while including real-world data to provide the most relevant and helpful guide for readers around the world. At Mr. Gamble, the players' safety and satisfaction are our top priority — you can rely on us to get the best possible offers from licensed online casinos.

What’s the Biggest Online Casino in the World?

The world's top online casino is Flutter Entertainment. Just like Entain, you might not be too familiar with the biggest online casino in the world due to the name. But underneath Flutter there’s another array of international brands which you’ll be all too familiar with.

In the UK, Sky Betting & Gaming, Paddy Power, Betfair, Pokerstars and Tombola are all brands we’re well aware of. Then there’s the US giant FanDuel as betting and gaming gets legalised more and more on a state-by-state basis.

Flutter’s brands each have a wide variety of games available to punters. Looking closer at Paddy Power, PP Games has all of your favourite slots. Fishin’ Frenzy, Reel King, Age of the Gods, Fishin’ Bonanza, Sahara Riches and more all feature prominently alongside Table Games, Megaways jackpots, Bingo and Live Casino too.

Little known this side of the pond would be Junglee Games, another one of Flutter’s arms – the fastest-growing skill games company in India and South-East Asia. The casino is a little different from what you’d find over here – given legislation around skill-based gaming and the RNG mechanics of slots. You’re able to play Rummy (something firmly embedded into Indian culture), plus ‘Spin-n-go’ and ‘Beat The Legend’ Rummy too. Junglee has over 500 employees and a whopping 50 million users across South East Asia.

It's not just Junglee who you might not know. Take Adjarabet, the prime sponsor of both the Georgian national basketball team and national water polo team as well as holding name rights to the Adjarabet Arena, the home of Georgian football champions FC Dinamo Batumi. They’ve been going for over 20 years, and have well over 1,000 employees that help bring Flutter’s famous Betfair Exchange, plus poker, casino and sports to Georgia and Armenia too.

What’s the Largest Online Casino in the UK?

The largest online casino in the UK is likely Entain. While you might not recognise the name, Entain is one of the world’s largest gambling companies and has lots of very familiar names under its umbrella.

You might be most familiar with high-street staples Ladbrokes and Coral both of which have popular online casino sections too. Entain’s casino led brands include PartyCasino, Gala Spins, Gala Casino and even websites like Gala Bingo have a dedicated slots section where you can have a spin too.

Do you know what all of these brands mean? More free spins, more sign-up bonuses and given that they’re all under the same umbrella, the registration process and approval on registration should also be lovely and easy.

You may have heard adverts for Foxy Bingo and Foxy Games on your radio too, which you’ll now be unsurprised to hear are also from Entain. Each of the biggest online gambling sites listed above have a great variety of table games, slots and live casino too. If you’re someone that enjoys a bet on football as much as they do a quiet night in on Fishin’ Frenzy then Coral and Ladbrokes may be best for you.

If you fancy yourself as Daniel Negreanu and play a bit of online poker, then you’ll be happy to know that PartyPoker has a pretty comprehensive library of slots as well as one of the industry’s most recognised poker downloadable software. Under Entain, the biggest online casino UK, you’re likely to find at least one site for you. Whether it’s bingo, poker, slots or roulette – there’s a site for everyone.

Frequently Asked Questions

Which online casino has the most slots?

While that’s just one example, we’re lucky now to live in a time where the best online gambling sites simply wouldn’t exist if they didn’t have a wide variety of games and slots. Premium slots and the most well-known titles are often across each and every site, and with Megaways and Progressive Jackpot slots there’s games that are shared between sites to give you the chance to win even bigger prizes.

How do I deposit with the best online casino?

There are several different payment options with all the best online casinos. Some of them that we’ve covered in this article will typically use the more traditional means, including debit card, bank transfer, and e-wallets such as Neteller and PayPal.

On the biggest online casinos, cryptocurrency is something that’s not necessarily supported yet. Due to the complexity (or non-existence) of regulation around the use of cryptocurrency around the world it’s something that casinos that offer in multiple regulated jurisdictions are cautious about accepting.

Hopefully, this shouldn’t be an issue, though, as fast withdrawals and deposits are a staple to run a good service and stay ahead of competition.

Do the biggest online gambling sites also offer sports and bingo?

Absolutely, they offer sports, bingo, as well as live casino games in addition to their large slots collection. To be the world’s biggest, you have to have more than just a few pretty slot machines on a website. 

Make sure you have a good look on each site, to find the best sign-up bonuses, be aware of any rollover requirements, and choose the best site for you.

    • avatar-Kirill Tsernov
      Kirill TsernovContent Creator
      Kirill is Mr. Gamble's Content Creator with a passion for writing. Being fan of gaming himself, he wants to make sure that everybody gets a fair playing experience...
    • avatar-Jonas Kyllönen
      Jonas KyllönenCreative Director
      Jonas is a veteran within the iGaming business. His passion is to provide truthful and helpful information for online gaming enthusiasts globally...
    • Silver Portugov is the Chief Business Officer at Mr. Gamble with a wealth of experience in the iGaming scene. The knowledge Silver has acquired in the industry allows him not only to come up with and implement successful business initiatives but also to build strong relationships with partners...