Mswati III (born Makhosetive Dlamini; 19 April 1968) is the Ngwenyama (King) of Eswatini and head of the Swazi royal family since 1986. He is the head of an absolute monarchy, holding executive authority over all branches of government and constitutionally immune from prosecution. Along with his mother Queen Ntfombi, Mswati is the last remaining absolute monarch in Africa and one of twelve remaining absolute monarchs worldwide.

Under the constitution, the king is commander-in-chief of the defence force and commissioner-in-chief of police and correctional services, and exercises influence over local government through traditional chiefs. In 2018, Mswati promulgated a decree renaming the country from Swaziland to Eswatini, restoring its pre-colonial name. Political activism and dissent are regulated under laws including those against sedition. Protests calling for political reform from 2021 onwards were dispersed and a number of activists were arrested.

Eswatini faces significant economic challenges: in 2022, an estimated 32% of the population lived below the US$2.15/day international poverty line (measured by purchasing power parity in 2017) while 55% fell below the lower-middle-income country threshold of $3.65/day. The government exercises influence over state broadcast media, while a growing number of independent online outlets operate in the country.

Mswati III was born Makhosetive Dlamini on 19 April 1968 at Raleigh Fitkin Memorial Hospital, Manzini, as the son of Sobhuza II (who had 70 wives during his life of 82 years) and Ntfombi.

When King Sobhuza II died on 21 August 1982, the Great Council of State (the Liqoqo) selected the 14-year-old prince Makhosetive to be the next king.

Mswati was introduced as crown prince in September 1983 and was crowned king on 25 April 1986, six days after turning 18, making him the youngest reigning monarch in the world at the time. He inherited an absolute monarchy from his father, who had ruled by decree since 1973 and banned all political parties.

Mswati III is Africa's last absolute monarch in the sense that he has the power to choose the prime minister, other top government posts and top traditional posts. Despite his role in appointing such positions, Mswati is still required to get special advice from the queen mother and council when choosing positions such as prime minister; similarly, in matters of cabinet appointments, Mswati is advised by the prime minister. Mswati ruled by decree, but he chose to restore the nation's Parliament, which had been dissolved by his father in order to ensure concentration of power remained with the king. Parliamentarians are appointed either by Mswati himself (two-thirds of the senators and ten deputies) or elected by traditional chiefs close to power. Close to the evangelical churches, he banned divorce and the wearing of miniskirts.

In an attempt to mitigate the HIV/AIDS pandemic in 2001, the king used his traditional powers to invoke a time-honoured chastity rite (umcwasho) under the patronage of a princess, which encouraged all Swazi maidens to abstain from sexual relations for five years. This was last done under Sobhuza II in 1971. This rite banned sexual relations for Swazis under 18 years of age from 9 September 2001 to 19 August 2005. However, two months after imposing the ban, Mswati violated the decree by choosing a 17-year-old liphovela (royal fiancée) as one of his wives.