List of national flags by design

A national flag is a one that represents and symbolizes a country or nation-state. Flags — and the related (royal) standards, ensigns, banners, and pennons / pennants — come in many shapes and designs, which often indicate something about what the flag represents, but generally national flags are rectangular or sometimes square-shaped.

Common design elements of flags include shapes as charges — such as crescent moons, crosses, stars, stripes, and suns — layout elements such as including a canton (a rectangle with a distinct design, such as another national flag), and the overall shape of a flag, such as the aspect ratio of a rectangular flag — whether the flag is square or rectangle, and how wide it is — or the choice of a non-rectangular flag. Sometimes these flags are used as a short-hand guide to represent languages on say, tourist information or versions of websites on internet.

Many countries with shared history, culture, ethnicity, or religion have similarities in their flags that represent this connection. Sets of flags in this list within the same category may represent countries' shared connections — as with the Scandinavian countries exhibiting the Nordic cross on their flags — or the design similarity may be a coincidence — as with the red and white flags of Indonesia and Monaco and Poland.

For clarity, unless stated, all flags shown are the civil flag of the nation state / country recognised as such by the United Nations — the state flags, (usually those of the government), along with the flags of autonomous countries, regions, and territories of a UN nation state are annotated in italics as such.

Most flags are rectangular / oblong. In Nordic nations, some have swallowtail shapes as the state flag, though the civil flag is oblong. The only nation state to fly a civil flag that is non-rectangular is   Nepal .

A great many national flags have a single defined aspect ratio. The most common aspect ratio is 2:3, followed by 1:2, with only a few being 1:1 (square-shaped). Some nations' flags have multiple acceptable ratios, or do not define any ratio at all, such as the Union Jack of the United Kingdom having its commonest aspect ratios of 1:2 followed by 2:3.

The following are the government / state flag only — the national civil flag is without the coat of arms.

Notably, the Union Jack features in many territorial and sub-national flags usually based on the Red Ensign, (e.g.  Bermuda), or Blue Ensign, (e.g.  New South Wales). The British Ensign is used in a few cases with backgrounds of other colours, (e.g.  The British Antarctic Territory and  Niue), or a unique pattern in the field, (e.g.  The British Indian Ocean Territory and  Hawaii). Some flags use the Union Jack other than at the canton, (e.g.  British Columbia). Unofficial flags also use it, (e.g.  The Ross Dependency of Antarctica).

• Keyword list at Flags of the World
• Extensive list of similar flags from around the world