Litvinovich overcame nerves to retain his title from the Tokyo Olympics with a score of 63.090, beating silver medallist China's Wang Zisai by more than a point. Wang's compatriot Yan Langyu took bronze.
"Of course, there was a little bit of nerves both before and during the competition," Litvinovich told reporters.
"I tried to switch my attention, talked to the coach, and didn't watch how the guys were performing.
"The opponents showed strong results, this could only throw off my mood. Overall, defending the title of champion of the Games, that's excellent."
After securing the victory, he stood atop the podium as the neutral athlete flag was raised and the orchestral anthem for neutral athletes rung out at Bercy Arena.
With the win, Litvinovich became the first athlete to claim multiple gold medals in the sport, which was added to the Olympic programme at the Sydney Games in 2000.
Teams from Russia and Belarus have been banned from taking part in the Games over Moscow's invasion of Ukraine, with Belarus having been used as a staging ground.
Only certain athletes have been authorised by the International Olympic Committee to compete as Individual Neutral Athletes after undergoing a screening process designed to root out anyone who has publicly supported the war or military.
Earlier on Friday, Litvinovich's compatriot Viyaleta Bardzilouskaya clinched silver in the women's trampoline final to claim the first medal of any colour for a neutral athlete in a close final won by Britain's Bryony Page.
"Dear Ivan, You are our pride!" Belarusian President Alexander Lukashenko said in a statement on his official website.
"Thank you for the Olympic gold. Millions of Belarusians today admire your will to win, determination and strength of character.
"Winning the Olympics is a huge achievement, and defending the title of Olympic champion is a sporting achievement that puts you on par with the most outstanding athletes in the world.
"I sincerely congratulate the coaches and specialists who invested their talent and skills in this victory.
"The Belarusian trampoline school has once again demonstrated the highest class and confirmed its well-deserved leadership on the world stage."