There are several Muslim countries that currently feature the crescent moon and star on their national flag, although the crescent moon is not generally considered to be a symbol of Islam. If the survey is broadened historically, there are examples of even more national flags that have made use of the crescent moon.
A surprisingly diverse group of nations feature this symbol, although the color, size, orientation and design features do vary widely from country to country.
Algeria is located in northern Africa and gained independence from France in 1962. Ninety-nine percent of Algeria's population is Muslim.
Algeria's flag is half green and half white. In the center is a red crescent and star. The white color represents peace and purity. Green represents hope and the beauty of nature. The crescent and star symbolize faith and are colored red to honor the blood of those killed fighting for independence.
Azerbaijan is located in Southwestern Asia, and it gained independence from the Soviet Union in 1991. Ninety-three percent of Azerbaijan's population is Muslim.
Azerbaijan's flag features three equal horizontal bands of blue, red and green (top to bottom). A white crescent and eight-pointed star are centered in the red band. The blue band represents Turkic heritage, red represents progress and green represents Islam. The eight-pointed star signifies the eight branches of the Turkic people.
Comoros is a group of islands in Southern Africa, located between Mozambique and Madagascar. Ninety-eight percent of Comoros' population is Muslim.
Comoros has a relatively new flag, which was last changed and adopted in 2002. It features four horizontal bands of yellow, white, red and blue (top to bottom). There is a green isosceles triangle along the side, with a white crescent and four stars within it. The four bands of color and the four stars represent the four main islands of the archipelago.
Malaysia is located in Southeast Asia. Sixty percent of Malaysia's population is Muslim.
Malaysia's flag is called the "Stripes of Glory." The fourteen horizontal stripes (red and white) represent equal status of the member states and the federal government of Malaysia. In the upper corner is a blue rectangle representing the unity of the people. Inside it is a yellow crescent and star; yellow is the royal color of the Malaysian rulers. The star has 14 points, which signifies the unity of the member states and the federal government.
The Maldives is a group of atolls (islands) in the Indian Ocean, southwest of India. All of the Maldives' population is Muslim.
The Maldives' flag has a red background which signifies the bravery and blood of the nation's heroes. In the middle is a large green rectangle, representing life and prosperity. There is a simple white crescent in the center, to signify the Islamic faith.
Mauritania is located in north-western Africa. All (100%) of Mauritania's population is Muslim.
Mauritania's flag features a green background with a gold crescent and star. The colors on the flag signify Mauritania's African heritage, as they are traditional Pan-African colors. Green may also represent hope, and gold the sand of the Sahara Desert. The crescent and star signify Mauritania's Islamic heritage.
Pakistan
Pakistan is located in southern Asia. Ninety-five percent of Pakistan's population is Muslim.
Pakistan's flag is predominantly green, with a vertical white band along the edge. Within the green section is a large white crescent moon and star. The green background represents Islam, and the white band represents Pakistan's religious minorities. The crescent signifies progress, and the star represents knowledge.
Tunisia
Tunisia is located in northern Africa. Ninety-eight percent of Tunisia's population is Muslim.
Tunisia's flag features a red background, with a white circle in the center. Inside the circle is a red crescent moon and a red star. This flag dates back to 1835 and was inspired by the Ottoman flag. Tunisia was part of the Ottoman Empire from the late 16th century until 1881.
Turkey
Turkey is located on the border of Asia and Europe. It has applied to become a member of the European Union, but progress temporarily halted in 2016 due to concerns about human rights. Ninety-nine of Turkey's population is Muslim.
The design of the flag of Turkey dates back to the Ottoman Empire and features a red background with a white crescent and white star.
Turkmenistan
Turkmenistan is located in Central Asia; it became independent from the Soviet Union in 1991. Eighty-nine percent of Turkmenistan's population is Muslim.
The flag of Turkmenistan is one of the world's most detailed designs. It features a green background with a vertical red stripe along the side. Inside the stripe are five traditional carpet-weaving motifs (symbolic of the country's famed carpet industry), stacked above two crossed olive branches, which signify the country's neutrality. In the upper corner are a white crescent moon (symbolizing a bright future) along with five white stars, representing the regions of Turkmenistan.
Uzebekistan
Uzbekistan is located in Central Asia and became independent from the Soviet Union in 1991. Eighty-eight percent of Uzbekistan's population is Muslim.
Uzbekistan's flag features three equal horizontal bands of blue, white, and green (top to bottom). Blue represents water and sky, white represents light and peace, and green represents nature and youth. Between each band are thinner red lines, representing "the tributaries of the power of life flowing through our bodies" (translation from Uzbek by Mark Dickens). In the upper-left corner, there is a white crescent moon to signify Uzbek heritage and independence, and 12 white stars representing either the 12 districts of the nation or, alternatively, 12 months in a year.