The track was named as one of best songs of 2019 by several publications.
Abby Aguirre of Vogue described it as a "romantic, haunting, waltzy, singer-songwritery nugget".
The video was filmed in a set in Hollywood, California.
In Canada, it peaked at number seven on the Canadian Hot 100.
"Lover" received a nomination for Song of the Year at the 62nd Grammy Awards.