Government officials and cadres at all levels must not smoke in public venues including schools, hospitals, sports and cultural centres and public transportation vehicles and vessels, according to a circular from the party's central committee and the State Council, or the cabinet.
China's health authorities already banned people from lighting up in indoor public places in 2011, although the rule is not seriously enforced or obeyed in a country that has more than 300 million smokers.
Smoking and tobacco-made products are also prohibited during any official activities, the statement said, such as meetings and government-sponsored forums.
No public funds should be used to pay for tobacco-related consumption, it added.
The Sunday announcement came amid a sweeping and widely-publicised government crackdown on corruption, excessive spending and extravagance under China's President Xi Jinping, who came into power a little over a year ago.
Cigarettes are one of the most popular gifts for networking and getting business done in China, partly as they are small in size and so draw little attention from others.
In 2009, a property official in the eastern city of Nanjing was sentenced to 11 years in jail for taking bribes after Internet users identified him as having cigarettes that sold for as much as 150 yuan ($25) a pack.
Earlier this month, authorities also ordered that shark fins, bird nests and wild animal products -- all favourite offerings in Chinese tradition to show off wealth and give a premium feel -- must be banned from official reception dinners.
But critics say no systemic reforms have been introduced to increase transparency to help fight endemic graft.