The Serbian Cyrillic alphabet (Serbian: Српска ћирилица, Srpska ćirilica, IPA: [sr̩̂pskaː t͡ɕirǐlitsa]), also known as the Serbian script, (Српско писмо, Srpsko pismo, Serbian pronunciation: [sr̩̂psko pǐːsmo]), is a standardized variation of the Cyrillic script used to write Serbo-Croatian, namely its Serbian and Bosnian (mainly in Republika Srpska) standard varieties. It originated in medieval Serbia and was significantly reformed in the 19th century by the Serbian philologist and linguist Vuk Karadžić.

The Serbian Cyrillic alphabet is one of the two official scripts used to write modern standard Serbian, the other being Gaj's Latin alphabet. Karadžić based his reform on the earlier 18th-century Slavonic-Serbian script. Following the principle of "write as you speak and read as it is written" (piši kao što govoriš, čitaj kao što je napisano), he removed obsolete letters, eliminated redundant representations of iotated vowels, and introduced the letter ⟨J⟩ from the Latin script. He also created new letters for sounds unique to Serbian phonology. Around the same time, Ljudevit Gaj led the standardization of the Latin script for use in western South Slavic languages, applying similar phonemic principles.

As a result of these parallel reforms, Serbian Cyrillic and Gaj’s Latin alphabet have a one-to-one correspondence. The Latin digraphs Lj, Nj, and Dž are treated as single letters, just as their Cyrillic counterparts are. The reformed Serbian Cyrillic alphabet was officially adopted in the Principality of Serbia in 1868 and remained the sole official script into the interwar period. Both scripts were recognized in the Kingdom of Yugoslavia and the Socialist Federal Republic of Yugoslavia. During the latter period, Gaj’s Latin alphabet gained greater prominence, especially in urban and multiethnic contexts.

Today, both scripts are in official use for Serbian. In Serbia, Cyrillic has the constitutional status of "official script", while the Latin script is designated as "script in official use" for minority and practical purposes. Cyrillic is also an official script in Montenegro and Bosnia and Herzegovina, alongside the Latin alphabet.

Serbian Cyrillic is in official use in Serbia, Montenegro, and Bosnia and Herzegovina. Although Bosnia and Herzegovina officially recognizes both the Cyrillic and Latin scripts, the Latin alphabet is predominantly used in the Federation of Bosnia and Herzegovina, while Cyrillic is more commonly used in Republika Srpska. In Croatia, the Serbian language is officially recognized as a minority language, and the use of Serbian Cyrillic is legally protected in areas with significant Serbian populations. However, the use of Cyrillic on bilingual signs has provoked protests and acts of vandalism in some communities.

Serbian Cyrillic is widely regarded as a key symbol of Serbian national and cultural identity. In Serbia, all official documents are printed in Cyrillic only, even though, according to a 2014 survey, 47% of Serbian citizens reported primarily using the Latin script, while 36% reported using Cyrillic.

The following table provides the upper and lower case forms of the Serbian Cyrillic alphabet, along with the equivalent forms in the Serbian Latin alphabet and the International Phonetic Alphabet (IPA) value for each letter. The letters do not have names, and consonants are normally pronounced as such when spelling is necessary (or followed by a short schwa, e.g. /fə/).:

Summary tables