The 69-year-old troubleshooter has been a confidante of President Xi since "they were young" and helped set up China's first investment bank with Morgan Stanley in the 1990s.
Like Xi, Wang will also not have any tenure as China's rubber-stamp parliament National People's Congress (NPC) on March 11 amended the constitution removing the two-term limit for the president and vice President.
"Wang Qishan will exercise power because he's Xi's deputy, not because he's vice president", said June Teufel Dreyer, a political-science professor at the University of Miami.
Last Sunday, the Congress adopted a constitutional amendment to scrap the limit of 2 five-year terms for president and vice president.
While most of Xi's power flows from his roles as party chief and supreme military commander, being president - or "chairman" in Chinese - gives him legal standing as head of state.
"Our Chairman Xi is too great, truly he is too great", said Du Meishuang, a Chinese opera singer and delegate from Chairman Mao's home province of Hunan.
After stepping down in October from the Politburo Standing Committee, the inner sanctum of party power, Mr. Wang continued to meet informally with visiting influential foreigners.
The ceremony - which took place after Xi received unanimous support from lawmakers to serve a second term as president - was a symbolic move to show the significance of the constitution, which was revised last week to include Xi's political theory, "Xi Jinping Thought".
The legislature also confirmed Wang Qishan - a well-known economic reformer who oversaw Xi's signature anti-corruption campaign - as vice-president.
While Xi's reappointment was assumed, there had been some speculation about Wang.
Mr. Wang is widely respected-and feared-for directing the most aggressive, sustained anticorruption clampdown the party has seen in three decades.
After the vote was announced in Beijing's Great Hall of the People, Wang bowed and then walked over to Xi to shake his hand.
Observer said that Wang would be among a new, stronger foreign policy team to be fully unveiled on Monday with the election of the cabinet.
"All Chinese are looking forward" to Xi continuing on, said Zhang Fanhua, a delegate from Anhui, as he hurried into the falling snow.