It was carefully staged in the grandiose Great Hall of the People on the edge of Tiananmen Square in Beijing.
He was also unanimously re-elected chairman of the Central Military Commission (CMC).
The institutional reform plan of the State Council was submitted to the on-going first session of the 13th National People's Congress for deliberations.
Xi took office as president in 2013 and hasn't said how many additional five-year terms he intends to serve. His reelection went unopposed, as nobody from the almost 3,000 Chinese legislature members voted against Xi, who first took the reins in 2013.
Yanmei Xie, a China policy analyst for Gavekal Dragonomics in Beijing, said appointing Wang could extend decision-making beyond the seven-member Politburo Standing Committee, the party's top body and a key component of the collective leadership system set up after Mao's tumultuous rule.
When he was vice premier, Wang periodically travelled to the United States, where President Barack Obama once gave the Chinese delegation a signed basketball that the official held up at a press conference. From India's perspective for the new line-up of officials, China's Foreign Minister Wang Yi was widely expected to be elevated to be State Councillor which makes him the top diplomat of the country.
US helicopter crash in Iraq kills all aboard
The names of those killed - everyone on board - will be released after next of kin have been notified, the statement added. The US acknowledges that it has about 5,200 troops in Iraq that are part of a coalition fighting Islamic State militants.
This is a crucial period for President Xi, who has sidelined his critics and rivals and seen his "Thought on Socialism with Chinese Characteristics for a New Era" enshrined in the Communist Party of China's constitution. His rise to the top echelons of the party took place in 2012 when he was appointed to the Standing Committee.
How a more prominent role for Wang as vice president would work is still uncertain.
Beijing-based political commentator Zhang Lifan expects Wang to focus on thorny U.S.
"Wang Qishan has a good reputation here in Washington, he is regarded as an effective and capable fixer", she said, adding he is "a leader that can make hard decisions and a very approachable negotiation partner".
Wang, 69, said to be Xi's most trusted aide, spearheaded an anti-graft campaign which made him China's most feared man.
The votes cap months of Communist Party conclaves and pageantry that confirmed Xi's status as arguably the world's most powerful leader. "Because in the past, the Party leader skips a generation to appoint the following leader", Yen said, referring to the practice since Deng of the incumbent being able to appoint the leader who follows his immediate successor. In line with precedent, Xi himself has been reinstalled as the head of the People's Liberation Army, promising to accelerate collaborations between the military and the private sector as part of China's defense upgrade strategy.