The šajka?a (Serbian Cyrillic: ???????, pronounced [??jkat?a]) is the Serbian national hat or cap. Traditionally worn by men in the Serbian countryside, it is named after Serb river troops known as šajkaši, who protected the Austrian Empire against the Ottoman Turks in the 18th century. A popular nationalist symbol in Serbia since the beginning of the early 20th century, it is typically black, grey or green in colour and is usually made of soft, homemade cloth. It became widely worn by Serb men during the First Serbian Uprising and was a key component in the uniform of the Serbian military from the beginning of the 19th century until the end of the 20th century. Today, it is mostly worn by elderly men in rural communities.

The šajka?a is a traditional hat worn by men in the Serbian countryside. It is the national hat of Serbia and is believed to have originated in the Serbian region of Banat during the 18th century, when šajkaši (Serb river troops in the service of the Austrian Empire) guarded the Danube and Sava rivers against the Ottoman Empire and wore caps in the shape of an overturned chaika (Serbian: Šajka, ?????) boat. It became widely worn amongst Serbs at the time of the First Serbian Uprising, when the men of Serbian revolutionary Kara?or?e Petrovi? began discarding their Turkish fezzes in favour of the cap.

The typical cap of peasants from the Šumadija region of Serbia, the šajka?a eventually acquired a dual purpose: during times of peace it was worn in the countryside, and in wartime it became part of the standard Serbian military uniform. During World War I, the cap was regularly worn by the soldiers of the Kingdom of Serbia. Serbia was eventually overrun by a combined Austro-Hungarian, German and Bulgarian invasion in 1915, and in 1916 the wearing of the šajka?a, alongside other Serbian folk attire, was outlawed by Bulgarian authorities in the wake of the Bulgarian occupation of southern Serbia. After the war, the wearing of the hat in Bosnia was made obligatory by Serbian authorities in place of the Turkish fez.
Serbian Partisans wearing the šajka?a (1941).

During World War II, the šajka?a was the standard hat worn by Serbian Chetnik irregulars in the Axis-occupied Kingdom of Yugoslavia. It was also worn by Serbian Partisans. After the war, it was replaced by the Titovka cap in the armed forces of communist Yugoslavia.

The šajka?a was worn by Serb soldiers during the breakup of Yugoslavia. Bosnian Serb reservists and paramilitaries wore the cap during the 1992–95 Bosnian War, and it was later adopted by Bosnian Serb forces to be the official headgear of the Army of Republika Srpska (Serbian: Vojska Republike Srpske, VRS).
Following the 1991 Battle of Vukovar, fought during the Croatian War of Independence, Croatian Serb authorities erected gravestones to the Serb soldiers who were killed fighting for the city. These were originally topped with sculptural evocations of the šajka?a cap. After Vukovar's reintegration into Croatia the gravestones were repeatedly vandalized, leading the Serb community in the town to replace them with more neutral gravestones without any overt military connotations. The 1999 NATO bombing of Yugoslavia saw McDonald's chains in Serbia promote their products by distributing posters and lapels which depicted the šajka?a standing atop the golden arches of the McDonald's logo in an attempt to bolster Serbian national pride.
The šajka?a has been a popular nationalist symbol in Serbia since the beginning of the 20th century. It is commonly worn by elderly men in the Serbian countryside, whereas Serbian youth wear traditional costumes only for folklore concerts.Designed with a V-shaped top in the form of an overturned chaika, the šajka?a is narrow and typically black or grey in colour.[16] It is usually made of soft, homemade cloth and is worn without any symbols during peacetime. During times of war, cockades featuring the Serbian double-headed eagle and the motto Only Unity Saves the Serbs are often seen on the cap.[3] The šajka?a worn by Serbian soldiers during World War I had a non-reflecting peak and was topped with a royal monogram