The symbolic move came on the final day of a week-long political summit in Beijing, the 19th CPC National Congress, at which Xi, 64, had pledged to lead the world's second-largest economy into a "new era" of international power and influence, reports the Guardian.
At a closing ceremony in the Great Hall of the People on Tuesday, it was announced that Xi's "Thought on Socialism with Chinese Characteristics for a New Era" had been written into the party charter.
"Our party shows strong, firm and vibrant leadership," Xi said in a brief address to more than 2,200 delegates.
"Our socialist system demonstrates great strength and vitality. The Chinese people and the Chinese nation embrace brilliant prospects.
"Today we more than 1.3 billion China's people live in jubilation and dignity. Our land radiates with enormous dynamism. Our Chinese civilisation shines with lasting splendour and glamour," the Guardian quoted Xi as saying
Chairman Mao founded the People's Republic of China in 1949.
Deng Xiaoping, the architect of China's economic opening, also boasts a school of eponymous ideology in the party charter, Deng Xiaoping Theory, but that was included only after his death in 1997.
Also on Tuesday, the CPC unveiled a new leadership, electing the 19th Central Committee to lead the party for the next five years.
The 19th CPC Central Committee will, in turn, elect the Political Bureau, the Standing Committee of the Political Bureau and the General Secretary at its first plenary session on Wednesday, reports Xinhua news agency.
According to the Party Constitution, the highest leading body of the CPC is the National Congress and the Central Committee it elects, and all constituent organisations and members of the Party are subordinate to the National Congress and the Central Committee.
The number of delegates to the National Congress and the procedure governing their election shall be determined by the Central Committee.