Today, an online slot machine can generally be categorized by the type of theme it has, and you will notice that several recurring themes are far more popular than others.

Slots are an incredibly popular casino game. Not only are there plenty of bonuses that revolve around the game – like crypto casino free spin – but the simplicity of the game is a draw, in addition to developers being able to apply many themes to the concept and gameplay.

Revealed on this page are today’s most popular online slot machine themes, along with a few examples of famous online slots that fall into one or more of these categories.

What are the most popular online slot machine themes

Here are some of the world’s most popular online slot machine themes you will most likely come across when you play at today’s best online casinos with thousands of slots from some of the iGaming industry’s multi-award-winning game development studios and software providers.
They include, in no particular order of importance, the following popular themes:

Ancient Egypt is a common theme in slots

- Ancient Civilization – sub-themes in this category include Ancient Egyptian-themed slots, Ancient Aztec-themed slots, Viking-themed slots, Ancient Greece-themed slots, and Ancient Inca-themed slots.

- Mythology – which is slightly different from above. Sub-themes in this category include Greek Mythology-themed slots, Roman-mythology-themed slots, Celtic/Pagan/Druid-themed slots, and Norse Mythology-themed slots.

- Sports – sub-themes in this category include Soccer/Football-themed slots, Horse Racing-themed slots, Fishing-themed slots, Cricket-themed slots, Basketball-themed slots, Ice Hockey-themed slots, and Car/Racing-themed slots, to name a few.

- American West – sub-themes in this category include Gunslinger-themed slots, Cowgirl/Cowboy-themed slots, Buffalo/Bison-themed slots, Native American-themed slots, and Wild West-themed slots.

- Leprechauns – sub-themes in this category include Luck O’ The Irish-themed slots, Clover/Shamrock-themed slots, Rainbow-themed slots, and Pots of Gold-themed slots.

- Science Fiction – sub-themes in this category include Alien Invasion-themed slots, Stars, Space & Galaxies-themed slots, Time Travel-themed slots, Hi-Tech-themed slots, Dinosaur-themed slots, and Aliens-themed slots.

- Horror – sub-themes in this genre include Halloween-themed slots, Zombie-themed slots, Paranormal/Ghost-themed slots, Monster-themed slots, and Werewolf-themed slots.

- Wildlife – sub-themes in this genre include Animals-themed slots (e.g. African Wildlife, Cats, Dogs, Monkeys, etc.), Nature-themed slots, Sahara Desert-themed slots, and Amazon Jungle-themed slots.

- Movies and TV Shows (aka branded online slots) – sub-themes in this category include Blockbuster/Hollywood Movie-themed slots, award-winning TV Series-themed slots, and even TV Game Show-themed slots.

- Mining – sub-themes in this category are Diamond Mining-themed slots and Gold Mining-themed slots.

Some online slots fall into one or more of these categories/themes, and you can now find hundreds of slots in each category.

In most countries, to play online slots for real money from a smartphone, tablet, laptop, or desktop computer, you must be at least 18 years old. However, the minimum legal age required to play online slots could be 19 (if you live in Canada) or 21 (if you live in the US).

A look at several famous online slots with popular themes

Some of the most famous online slots out there today with one of these popular themes are the Play’n GO’s Book of Dead online slot (Ancient Egypt), Stormcraft Studio’s Thunderstruck: Wild Lightning Link & Win online slot (Norse Mythology), and Pragmatic Play’s Wild Wild Riches: Luck of the Irish Megaways online slot (Leprechaun).

Other hit titles include Blueprint Gaming’s Diamond Mine Megaways online slot (Gold Mining), Playtech’s Age of the Gods: King of Olympus online slot (Greek Mythology), NetEnt’s Narcos: Mexico online slot (TV Series), and Microgaming/Games Global’s Jurassic Park online slot (Movie).

Are there any other popular online slot themes?

Yes. Apart from the ones mentioned above, you can also find hundreds of Asian-themed slots, Wealth and Luxury Lifestyle-themed slots, Holidays/Christmas-themed slots, and Steampunk-themed slots.

Others include Food-themed slots (e.g., sweets & candy, fruits, and vegetables), Love and Romance-themed slots, Summer/Winter-themed slots, War/Military/Conflict-themed slots, Underwater/Ocean-themed slots, Mexican-themed slots, Music-themed slots, and Pirate-themed slots, to name just a few.

Final note

The best thing to do would be to try out as many online slot themes as possible to see which ones you like the most. The games in each category tend to have plenty of bonus features and big jackpots to play for, and you can often play from as little as $/€/£0.10 or $/€/£0.20 per spin.