Statements were posted on the websites of schools, government agencies and local party organisations in the Xinjiang region, warning the ban was in place to protect the well-being of students and prevent the promotion of religion, the Associated Press reports.
The move comes amid tightened security in the region, which has been hit by a growing number of violent attacks.
Xinjiang is home to around nine million Uighurs, largely a Muslim ethnic minority, many of whom accuse China’s leaders of religious and political persecution.
The BBC cites a statement from state-run Bozhou Radio and TV University as saying: “We remind everyone that they are not permitted to observe a Ramadan fast.”
The channel’s Beijing correspondent says that while Beijing blames extremist Uighurs for growing violence, the ban is likely to be seen by many Muslims as an attack on their religion, thus exacerbating tensions.
Dilxat Raxit, spokesman in Germany for the rights group World Uyghur Congress, said: “This will lead to more conflicts if China uses coercive measures to rule and challenge Uighur beliefs.”
The practice of fasting during Ramadan is intended to teach Muslims “self-discipline, self-restraint and generosity”, and takes place during the daylight hours.
Sexual intercourse and profanity are also banned for the 30 day period, in a bid to become closer to Allah.
The region has faced similar bans in the past, with Al Jazeera reporting on local government orders in 2012 which also urged schools to ensure students did not enter mosques during the holy month.