What is most popular song?

According to Guinness World Records, the most popular song of all time is "We Are the World", released in 1985. The song was written by Michael Jackson and Lionel Richie, and recorded by the supergroup USA for Africa, which featured notable musicians such as Stevie Wonder, Paul Simon, Diana Ross, Bruce Springsteen, and Michael Jackson. "We Are the World" became a global hit and sold more than 25 million copies worldwide, with proceeds donated to humanitarian efforts in Africa. It also garnered multiple awards, including three Grammy Awards and an Academy Award for Best Original Song.