Murtadha Ansari

Murtadha al-Ansari al-Tostari
مرتضی الأنصاري التستري
TitleGrand Ayatollah
Personal life
Born1781
Died1864 (aged 8283)
Resting placeImam Ali Shrine
NationalityArab
Other namesSahib al-Makasib, Arabic: صاحب المكاسب
Sheikh al-Ta'ifa, Arabic: شيخ الطائفة
Relatives Jabir ibn Abd Allah al-Ansari (ancestor)
Religious life
ReligionIslam
InstituteNajaf Seminary
JurisprudenceTwelver Shia
Muslim leader
Based inNajaf, Iraq
PostGrand Ayatollah
Period in office1849–1864
PredecessorMuhammad Hasan al-Najafi
SuccessorMirza Shirazi

Grand Ayatollah Sheikh Murtadha al-Ansari al-Tostari (1781–1864; Arabic: مرتضی الأنصاري التستري) known as Shaykh al-Ta'ifah (Arabic: شيخ الطائفة, romanized: Shaykh al-Ṭāʾifah) was an Arab Islamic scholar who was “generally acknowledged as the most eminent jurist of the time". He is considered to have laid the foundation of modern Shii jurisprudence, and his style has been imitated more than any other classical scholar of Shia Islam.

Ansari has also been called the "first effective" model or Marja of the Shia or "the first scholar universally recognized as supreme authority in matters of Shii law".