"I'm Leaving It Up to You" is a song written by and originally performed by Don Harris and Dewey Terry in 1957. It was later popularized in 1963 by the American duo Dale and Grace, who took the song to number one on the Billboard Hot 100 chart. In 1974, Donny and Marie Osmond reached the top five on the US Hot 100 chart and peaked at number one on the Billboard Hot Adult Contemporary chart with their cover version.

"I'm Leaving It Up to You" first became popular when recorded by the duo Dale and Grace in 1963. Their version became a No. 1 hit in the United States on the Billboard Hot 100 for two weeks in late 1963. It was the first time a duet succeeded another duet at the top spot.

The single also spent two weeks atop the easy listening chart. It was the number 1 song on the Billboard Hot 100 chart when President John F. Kennedy was assassinated in Dallas, Texas. Dale and Grace were in Dallas on the day of the assassination and scheduled to perform that night as part of Dick Clark's Caravan of Stars (with Bobby Rydell, Jimmy Clanton, and Brian Hyland), and moments before the assassination had waved to the president's motorcade from a vantage point near their hotel.

In 1974, "I'm Leaving It Up to You" again became a chart-topping hit in the U.S. when brother and sister duo Donny and Marie Osmond covered it in September, it reached number 4 on the Hot 100 and number 1 on the easy listening chart. It also reached number 2 in the UK. Their version became a gold record.

...
Wikipedia