Mmanthatisi (also spelled 'Ma Nthisi, Mantatise, or Mantatisi; c. 1784 – 1847) was the leader of the Tlokwa people during her son's minority from 1813 until 1824. She came to power as the regent for her son, Sekonyela, following the death of her husband (the previous chief). She led the Tlokwa during the difaqane, the period of mass migration in Southern Africa which saw the tribe move from its original territory in what is now South Africa into present-day Lesotho.
Mmanthatisi's name at birth was Monyalue. She was the daughter of Mothaha, a chief of the Sia tribe, and was born in what is now South Africa's Free State province, in the area of the present-day city of Harrismith. At a young age, she was married off to a cousin, Mokotjo, who was the chief of the Tlokwa. Their first child, a daughter, was born around 1800, and she subsequently became known as simply Mmanthatisi, meaning "mother of Nthatisi" (her daughter's name). A second child, a son named Sekonyela, was born in 1804 and became heir to the chiefship, and a second son, Mota, was born later.
Mokotjo died in 1813, and Mmanthatisi became regent for Sekonyela, who was too young to rule. The Tlokwa practised the levirate marriage, and after being widowed she was consequently remarried to her brother-in-law, Molope, with whom she had another son. Due to the rise of the militaristic Zulu Kingdom, Mmanthatisi decided to move her tribe westward. In 1817, her warriors led a raid on the Ndwandwe, capturing many of their cattle. This and other victories led to an alliance with the Hlubi people, and an attack on the territory of Moshoeshoe (who would later become the first paramount chief of Basutolandi). It has been estimated that Mmanthatisi led between 35,000 and 40,000 when the expanded Tlokwa group was at its largest.
Mmanthatisi is credited with planning the strategies of her troops, but did not personally lead the Tlokwa into battle. On one occasion, she reputedly foiled an attack from a neighbouring tribe by assembling cattle, women, and children on a hilltop, which gave the attackers the impression that they were outnumbered despite the Tlokwa men being away on a separate raid. Sekonyela succeeded to the Tlokwa chiefship in 1824, but his mother remained a powerful influence until her death in 1847. Mmanthatisi spent the last years of her life in what is now northern Lesotho, living in isolated hilltop fortresses in the region close to present-day Ficksburg.