The lavish event to mark 80 years since Japan's defeat at the end of World War Two has been largely shunned by Western leaders, with Putin and Kim - pariahs in the West due to the Ukraine war and Kim's nuclear ambitions - the guests of honour.
Designed to project China's military might and diplomatic clout, it also comes as US President Donald Trump's trade tariffs and volatile policymaking strain its relations with allies and rivals alike.
"Today, mankind is faced with the choice of peace or war, dialogue or confrontation, win-win or zero-sum," Xi told a crowd of more than 50,000 spectators at Tiananmen Square on Wednesday, adding that the Chinese people "firmly stand on the right side of history".
Riding in an open-top limousine, Xi then inspected the troops and cutting-edge military equipment such as missiles, tanks and drones on display.
Helicopters trailing large banners and fighter jets flew in formation above during the 70-minute showcase thick with symbolism and propaganda which culminated in the release of 80,000 peace doves and colourful balloons.
Wearing a suit in the style of those worn by former leader Mao Zedong, Xi earlier greeted the more than 20 leaders saying "Nice to meet you" and "Welcome to China" in English.
Indonesian President Prabowo Subianto, facing widespread protests at home, made a surprise appearance.
Trump, in a post on Truth Social as the parade kicked off, highlighted the US role in helping China secure its freedom from Japan.
"Please give my warmest regards to Vladimir Putin, and Kim Jong Un, as you conspire against The United States of America," Trump added.
Trump had earlier told reporters he did not see the parade as a challenge to the United States and reiterated his "very good relationship" with Xi.
Xi has cast World War Two as a major turning point in the "great rejuvenation of the Chinese nation", in which it overcame the humiliation of Japan's invasion to become an economic and geopolitical powerhouse.
Earlier this week, Xi unveiled his vision of a new global order at a regional security summit, calling for unity against "hegemonism and power politics", a thinly veiled swipe at his rival across the Pacific Ocean.
"Xi feels confident that the table has turned. It's China that is back in the driver's seat now," said Wen-Ti Sung, fellow at the Atlantic Council's Global China Hub, based in Taiwan.
"It's been Trumpian unilateralism rather than China's wolf warrior diplomacy when people talk about the leading source of uncertainty in the international system," he added.
Beyond the pomp, analysts are watching whether Xi, Putin and Kim may signal closer defence relations following a pact signed by Russia and North Korea in June 2024, and a similar alliance between Beijing and Pyongyang, an outcome that may alter the military calculus in the Asia-Pacific region.
Putin has already used the occasion to seal deeper energy deals with China, while the gathering has given Kim an opportunity to gain implicit support for his banned nuclear weapons.
Kim, debuting in his first major multilateral event, became the first North Korean to attend a Chinese military parade in 66 years.
"The parade allows Xi to focus the world's attention on its impressive strides in modernising its military hardware, while overshadowing the stubborn challenges afflicting the PLA, most notably the continued purges rolling through the ranks of its most senior officers," said Jon Czin, a foreign policy analyst at Brookings Institution, a US-based think tank.
Nothing was left to chance for the milestone gathering.
Major roads and schools were closed in Beijing for the parade, the culmination of weeks of painstaking security preparations and midnight rehearsals.
with AP
