According to Guinness World Records, Irving Berlin's "White Christmas" performed by Bing Crosby in 1942 is the best-selling single worldwide, with estimated sales of over 50 million copies. The song, recognized as "the best-selling single of all time", was released before the pop/rock singles-chart era and "was listed as the world's best-selling single in the first-ever Guinness Book of Records, published in 1955 and still retains the title more than 50 years later".
Guinness World Records also states that double A-side charity single "Candle in the Wind 1997"/"Something About the Way You Look Tonight" in 1997 by Elton John (rewritten as a tribute to Diana, Princess of Wales, rather than Marilyn Monroe in the original 1973 version), is "the biggest-selling single since UK and US singles charts began in the 1950s, having accumulated worldwide sales of 33 million copies". This makes it the second best-selling physical single of all time
