A national flag is a flag that represents and symbolizes a country. Flags come in many shapes and designs, which often represent something about the country or people that the flag represents. Common design elements of flags include shapes such as stars, stripes, and crosses, 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 to represent languages. 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, or the design similarity may be a coincidence.

Circle

One circle in center

One circle on hoist

One broken or implied circle

Coat of arms

Crescent

Facing up

Facing fly

Facing diagonally

Cross

Upright centred cross

Saint George's Cross

Nordic Cross

Nordic Cross in two colors

Nordic Cross in three colors

Diagonal cross

St. Andrew's Cross

Upright and diagonal centred crosses

One cross in emblem

Union Jack

Historically

Additionally, the Union Jack features in many territorial and sub-national flags. These are often Red Ensigns (e.g., ) or Blue Ensigns (e.g., and ). A small number have backgrounds of other colors (e.g. and ) or a unique pattern in the field (e.g. and ). A small number put the Union Jack somewhere other than the canton (e.g. ). Unofficial flags, such as also use it.

Living organism

Human and body parts

Animal

Bird

Eagle

Livestock

Lion

Other

Historically

Plants

Historically

Fleur-de-lis

Objects

Astronomical

Sun

Moon

Weaponry

Ships

Machine, tool, or instrument

Map

Building

Book

Headgear

Other symbols

Star

Five-pointed star

One five-pointed star in center

One five-pointed star on hoist

One five-pointed star on canton

Many equal five-pointed stars

Many equal five-pointed stars in circle pattern

Many unequal five-pointed stars

Six-pointed star

One six-pointed star

Many equal six-pointed stars

Many-pointed star

One many-pointed star

Many many-pointed stars

Stars and stripes

Stars and alternating stripes

Stars and varying stripes

Stars in southern cross pattern

Text

Country name

Motto

Country name and motto

Other texts

Quadrilateral

Bordering stripe

Upper left quarter

Historically

Vertical stripe on hoist

Four parts

Two equal squares and two equal rectangles meeting on hoist

Four equal rectangles meeting at center

Triangle

Triangle(s) in center

Triangle(s) on hoist

Triangles meeting at center

Diagonal stripes

Two diagonal stripes

Three fimbriated diagonal stripes

Many radiating diagonal stripes

Pall

Horizontal stripes in two colors

Two horizontal stripes

Equal

Unequal

Three horizontal stripes

Equal

Thin-and-thick

Fimbriated thin-and-thick

Many horizontal stripes

Equal

Unequal

Horizontal stripes in three colors

Three horizontal stripes

Equal

Fimbriated equal

Unequal

Five horizontal stripes

Unequal

Horizontal stripes in many colors

Four equal horizontal stripes in four colors

Five equal horizontal stripes in five colors

Vertical stripes in two colors

Two equal vertical stripes

Two unequal vertical stripes

Two unequal serrated vertical stripes

Three equal vertical stripes

Three unequal vertical stripes

Vertical stripes in three colors

Three equal vertical stripes

Unique aspect ratio

Most common aspect ratio is 2:3, followed by 1:2. The following flags have a distinctive aspect ratio: