Iyasu II or Joshua II (Ge'ez ኢያሱ; 21 October 1723 – 27 June 1755) was nəgusä nägäst (throne name Alem Sagad, Ge'ez ዓለም ሰገድ ʿAläm Sägäd, "to whom the world bows") (19 September 1730 – 27 June 1755) of Ethiopia, and a member of the Gondar branch of the Solomonic dynasty. He was the son of Emperor Bakaffa and Empress Mentewab (also known by her Baptismal name of Welete Giyorgis).
The Empress Mentewab played a major role in Iyasu's reign, perhaps against her will. Shortly after he was proclaimed Emperor, a rival claimant assaulted the Royal Enclosure for eight days, only leaving the capital Gondar when an army of 30,000 from Gojjam appeared. Although the rebels failed to penetrate its walls, nonetheless much of Gondar was left in ruins. Instead of taking the title of regent upon the succession of her underage son, Empress Mentewab had herself crowned as co-ruler, becoming the first woman to be crowned in this manner in Ethiopian history. Empress Mentewab wielded significant authority throughout the reign of her son, and well into the reign of her grandson as well.
During Iyasu II's reign, a Czech Franciscan Remedius Prutky visited his kingdom, and engaged Iyasu in talks about religion and European politics. Although he and his two companions were popular because of their medical skills, Prutky and his Catholic companion were asked to leave because of complaints from the local clergy after a year.
Despite Mentewab's counsel, Iyasu proved to be an ineffectual monarch. According to Paul Henze, Iyasu "came under criticism for devoting too much time to pleasure (he loved hunting) and for spending too many resources on embellishing the capital, paying foreign workmen, and importing luxury goods, ornaments and mirrors from Europe." Prutky, on the other hand blamed Iyasu's constrained revenues to the actions of his mother Mentewab: "Since the youthful emperor Jasu had only reached the age of eight when he ascended the throne, his mother the Queen divided out the provinces among the chief ministers in such a way that, at the time of my sojourn there, the Emperor, now over thirty years of age, saw his treasury diminished and scarcely enough for his ordinary expenses." Prutky adds that during the year Prutky was in Ethiopia (1752), the emperor was engaged in a struggle with his own sister over the revenues from Gojjam.