ఇస్లాంలో షియా ఇస్లాం లేదా 'షియా' అనునది ఒక శాఖ. వీరు సున్నీల తరువాత పెద్ద సంఖ్యలో గలరు. ముహమ్మద్ ప్రవక్త కాలంనుండే వీరు ప్రత్యేక వర్గంగా వుంటూ వచ్చారు. వీరు మహమ్మద్ ప్రవక్తపై విశ్వాసముంచరు అనే అపవాదు ఉంది. కాని ఇది నిజంగాదు. వీరు అహ్లె బైత్ (అనగా ప్రవక్తగారి కుటుంబం) పట్ల ఎక్కువగా తమ ప్రేమాభిమానాలు చాటుతారు. సున్నీలకు షియాలకు ప్రధాన తేడా, సున్నీలు ప్రధానంగా సున్నహ్ పట్ల తమ జీవితాలను ప్రతిబింబించేలా చూసుకుంటారు. షియాలు సున్నహ్ పట్ల అంతగా ప్రగాఢ విశ్వాసం ప్రకటించరు. షియాలయందు ప్రధానం ఇమామ్. ఈ ఇమామ్ పరంపర అలీ ఇబ్న్ అబీ తాలిబ్ (ప్రవక్తగారి అల్లుడు, ఫాతిమా గారి భర్త) నుండి ప్రారంభమైనది. సున్నీలు షరియా న్యాయశాస్త్రాలను పాటిస్తే, షియాలు జాఫరి న్యాయశాస్త్రం అవలంబిస్తారు. షియా ఇస్లాం అనేక శాఖలుగా విభజింపబడియున్నది. వీరిలో ప్రధానం ఇస్నా అసరియా (12 ఇమామ్ లను అనుసరించేవారు), మిగతావారు ఇస్మాయీలి, జైదియ్యా లు.

షియా ఇస్లాం (} "Shia", sometimes "Shi'a"; adjective "Shi'ite"), is the second-largest denomination of Islam, comprising 25% of the total Muslim population in the world. Shia Muslims, though a minority in the Muslim world, constitute the majority of the populations in Azerbaijan, Bahrain, Iran, and Iraq, as well as a plurality in Lebanon and Yemen.

In addition to believing in the authority of the Qur'an and teachings of Muhammad, Shia believe that his family, the Ahl al-Bayt (the "People of the House"), including his descendants known as Imams, have special spiritual and political rule over the community and believe that Ali ibn Abi Talib, Muhammad's cousin and son-in-law, was the first of these Imams and was the rightful successor to Muhammad, and thus reject the legitimacy of the first three Rashidun caliphs.

The Shia Islamic faith is broad and includes many different groups. There are various Shia theological beliefs, schools of jurisprudence, philosophical beliefs, and spiritual movements. The Shia identity emerged soon after the martyrdom of Hussain son of Ali (the grandson of the prophet Muhammad) and Shia theology was formulated in the second century and the first Shia governments and societies were established by the end of the ninth century.

An estimate of approximately 25% of the world's Muslims are Shia, which corresponds to about 400–450 million Shia Muslims worldwide. Shia Muslims also constitute over 40% of the population in Lebanon, over 45% of the population in Yemen, over 40% of the population in Kuwait, 25–35% of the population (primarily Alevi) in Turkey, 15% (primarily Bektashi) of the population in Albania, 25% of the population in Pakistan and 2% of population in Afghanistan. They also make up at least 15% to 31% of the Muslim populations in India and 15 to 20% in the United Arab Emirates, Syria and Saudi Arabia – although the total number is difficult to estimate due to the intermingling between the two groups and practice of taqiyya by Shiites.

Significant Shia communities exist on the coastal regions of West Sumatra and Aceh in Indonesia (see Tabuik). The Shia presence is negligible elsewhere in Southeast Asia, where Muslims are predominantly Shafi'i Sunnis.

A significant syncretic Shia minority is present in Nigeria, centered around the state of Kano (see Shia in Nigeria). East Africa holds several populations of Ismaili Shia, primarily descendants of immigrants from South Asia during the colonial period, such as the Khoja.

According to Shia Muslims community, one of the lingering problems in estimating Shia population is that unless Shia form a significant minority in a Muslim country, the entire population is often listed as Sunni. The reverse, however, has not held true, which may contribute to imprecise estimates of the size of each sect. For example, the 1926 rise of the House of Saud in Arabia brought official discrimination against Shia.

Shia Islam is divided into three branches. The largest and best known are the Twelver ( ""), named after their adherence to the Twelve Imams. They form a majority of the population in Iran, Azerbaijan, Bahrain and Iraq. Other smaller branches include the Ismaili and Zaidi, who dispute the Twelver lineage of Imams and beliefs.

The Twelver Shia faith is predominantly found in Iran (90%), Azerbaijan (85%), Bahrain (70%), Iraq (65%), Lebanon (40%), Kuwait (25%), Albania (20%), Pakistan (25%), Afghanistan (20%).

The Zaidi dispute the succession of the fifth Twelver Imam, Muhammad al-Baqir, because he did not stage a revolution against the corrupt government, unlike Zaid ibn Ali. They do not believe in a normal lineage, but rather that any descendant of Hasan ibn Ali or Husayn ibn Ali who stages a revolution against a corrupt government is an imam. The Zaidi are mainly found in Yemen.

The Ismaili dispute the succession of the seventh Twelver Imam, Musa al-Kadhim, believing his older brother Isma'il ibn Jafar actually succeeded their father Ja'far al-Sadiq, and did not predecease him like Twelver Shia believe. Ismaili form small communities in Afghanistan, Pakistan, Uzbekistan, Tajikistan, India, Syria, United Kingdom, Canada, Uganda, Portugal, Yemen, mainland China, Bangladesh and Saudi Arabia and have several subbranches.
సుహర్ వర్దియా
జాఫరి న్యాయపాఠశాల
షియా ఇస్లాం
సున్నీ ఇస్లాం