This is a repository containing lists of all countries worldwide in several formats. The data is taken from GeoNames and thus under CC BY license. I use it for Programmer Map which lists the best programmers in all countries and many cities worldwide.

There are currently three file formats: JSON, CSV, and PHP.

The JSON files are located in json/. There are two versions A readable version with indentation: json/countries-readable.json

[
    {
        "alpha_2": "AD",
        "alpha_3": "AND",
        "area": "468",
        "capital": "Andorra la Vella",
        "continent": "EU",
        "currency_code": "EUR",
        "currency_name": "Euro",
        "eqivalent_fips_code": "",
        "fips": "AN",
        "geoname_id": "3041565",
        "languages": "ca",
        "name": "Andorra",
        "neighbours": "ES,FR",
        "numeric": "020",
        "phone": "376",
        "population": "84000",
        "postal_code_format": "AD###",
        "postal_code_regex": "^(?:AD)*(\\d{3})$",
        "tld": ".ad"
    },
    // ...

And a compact version: json/countries.json

[{"alpha_2": "AD", "alpha_3": "AND", "area": "468", "capital": "Andorra la Vella", "continent": "EU", //...

The CSV file is located under csv/countries.csv. It uses semicolons as separators as there are commas in the country names. You can open CSV files in almost any spreadsheet software, e.g. Microsoft Excel, Libre Office Calc, etc.

phone;currency_name;geoname_id;alpha_2;currency_code;neighbours;area;numeric;capital;tld;eqivalent_fips_code;languages;postal_code_format;fips;postal_code_regex;alpha_3;continent;name;population
376;Euro;3041565;AD;EUR;ES,FR;468;020;Andorra la Vella;.ad;;ca;AD###;AN;^(?:AD)*(\d{3})$;AND;EU;Andorra;84000
971;Dirham;290557;AE;AED;SA,OM;82880;784;Abu Dhabi;.ae;;ar-AE,fa,en,hi,ur;;AE;;ARE;AS;United Arab Emirates;4975593
93;Afghani;1149361;AF;AFN;TM,CN,IR,TJ,PK,UZ;647500;004;Kabul;.af;;fa-AF,ps,uz-AF,tk;;AF;;AFG;AS;Afghanistan;29121286
...

The PHP file is located under php/array.php and contains the list of all countries in array notation.

<?php
$countries = [
    [
        "alpha_2" => "AD",
        "alpha_3" => "AND",
        "area" => "468",
        "capital" => "Andorra la Vella",
        "continent" => "EU",
        "currency_code" => "EUR",
        "currency_name" => "Euro",
        "eqivalent_fips_code" => null,
        "fips" => "AN",
        "geoname_id" => "3041565",
        "languages" => "ca",
        "name" => "Andorra",
        "neighbours" => "ES,FR",
        "numeric" => "020",
        "phone" => "376",
        "population" => "84000",
        "postal_code_format" => "AD###",
        "postal_code_regex" => "^(?:AD)*(\d{3})$",
        "tld" => ".ad",
    ],
    // ...

There are several similar projects you should also check out. Feel free to add yours.

• unicode-cldr/cldr-core: Lots of JSON data but hard to query and without geoname ids
• mledoze/countries: PHP generator, various formats and a lot of data but no geoname ids and weird ISO 639-3 codes that are hard to resolve (Austria has "bar" as language which is basically a German dialect)
• umpirsky/country-list: focused on localized versions and ISO only, no generator
• fayder/restcountries: Country data provided by a restful API (JSON)
• datasets/country-codes: CSV data with lots of codes for country representations (stuff like FIFA, IOC, etc.)

Picture licensed under CC0 by Lena Bell.