There are several ways that apply to most parts of the Western World:
1. Meetups – Meetup.com is probably the most useful tool for anyone trying to meet people. You can find meetups there centred around just about anything, but if you search near you for “atheist” and “skeptics” and “humanist”, you should be able to find something, no matter how remote your town or city is. I live in a town of 12,000 and 3 meetups come up for me.
2. Skeptics in The Pub – This began in ’99 in London and is now in a couple dozen countries. We have one where I live, so you probably have one where you live. It’s a super casual meetup over beers at your local pub, and each meetup is usually centred around a different topic meant to spark conversation and debate. If you want to find one near you, just search Google for your geographic region, city or town plus “skeptics in the pub”.
3. Humanist Associations – These things are everywhere apparently. I am even surprised by how many keep popping up. This is a wonderful way not only to meet fellow atheists and humanists, but also to do some good. Humanist associations usually have causes they support or fight for, such as death with dignity and LGBT issues. They often have meetings and attend events together such as Pride and lectures. They are also commonly known to make their own meetups as well, centered around dinners or outings. If you join your local humanist association, you can be sure you’ll come away from it with some lifelong friends.
4. CFI – The Center For Inquiry is an organization that is devoted to free inquiry, as the name suggests. They promote skepticism, science, humanism and secular values. The CFI keps itself extremely busy with tons of enjoyable events, such as lectures and talks, science events for kids, meetups, etc. The CFI is more prominent in Canada and the US but has events and chapters around the world. You can find out more about the CFI on their website: Center For Inquiry
5. Become a member and attend events at your local science-related facilities: planetariums, aquariums, museums, observatories, etc. Some of these places do an exceptional job of putting on enjoyable events for families. Hanging out around people who appreciate science certainly ups the odds of meeting a fellow nonbeliever.
6. Get online: Reddit, Twitter, Facebook, Pinterest, Instagram and Google+ all have large numbers of atheists and sometimes you can come across a few who live near you. Here are some of the more prominent online atheist communities:
Reddit: Atheism Rebooted
Reddit: Atheist Parents
Facebook: We Fucking Love Atheism
Pinterest: Freethinkers ~ Atheists
Pinterest: Freedom for (& from) Idolatry
How do you meet other atheists in your area? Let me know in the comments and I can continue to build this list.