President Xi Jinping has described the work of the United Front as one of the Communist Party's "magic weapons" in achieving China's "great rejuvenation", echoing a reference by Mao Zedong.
The United Front will oversee the State Ethnic Affairs Commission, and absorb the State Administration of Religious Affairs and the Overseas Chinese Affairs Office, the government said in a notice released by the official news agency, Xinhua.
The reshuffle, which groups the three State Council bodies under the control of the party's central committee, will strengthen "centralised and unified leadership", it added.
"This concentrating of the decision-making process within the party, rather than the government, is in line with the overall theme of the National People's Congress and the emphasis of the party's control over everything," said Willy Lam, a professor at the Chinese University of Hong Kong.
Lam, an expert in Chinese politics, was referring to an annual meeting of the rubber-stamp parliament that ended on Tuesday, after approving constitutional changes removing presidential term limits to allow Xi to stay in power indefinitely.
All the four bodies and the State Council Information Office, which doubles as the office of the party spokesman, did not immediately respond to Reuters' request for comment on Wednesday.
The United Front has broad aims to win support for Chinese political interests and build influence through measures such as co-opting and influencing the overseas Chinese diaspora and other well-connected groups outside the Communist Party.
It focuses on party priorities ranging from management of ethnic minorities and religion, Tibet and Xinjiang affairs, to Hong Kong and Macau, but is most closely tied to thwarting moves toward greater independence by Taiwan, aiming for its eventual "reunification".
Xi has elevated the importance of United Front work to levels not seen since the founding of the People's Republic in 1949.
Lam said the United Front's increasing importance within the Communist Party was in line with Xi's hardening stance toward self-ruled Taiwan.