The 73-year-old veteran was expected to perform at The Forum in Inglewood, California and the Allstate Arena in Rosemont, Illinois this week.
"We regret to inform you that Barry Manilow's two concerts scheduled for this week in Los Angeles and Chicago are currently being rescheduled.
"Barry is on doctors orders to rest due to sprained vocal chords. We are all very sorry for any inconvenience this may cause," a post on Manilow's Facebook page read.
"Tickets issued for the original dates will be honoured at the rescheduled dates.