The couple began dating in March 2015 and is said to have split after 15 months together. The breakup comes as a surprise as they celebrated their one-year anniversary in spring and Harris has recently been recovering after a serious car accident.
"There was no drama," a source told People magazine. "Things just don't work out sometimes."
The two were introduced to each other through mutual friend Ellie Goulding, because they were both "really tall." Once official, Harris and Swift were both relatively public with their affection for each other. In June 2015, the Scottish DJ praised his "girl" for taking on Apple Music, even taking on fellow singer Zayn Malik when the former One Direction member tweeted his disproval of Swift's action.
Swift was uncharacteristically open about her relationship at the iHeartRadio Music Awards in April, when she publicly thanked Harris in her speech and addressed him by his real name, Adam.
"For the first time, I had the most amazing person to come home to when the spotlight went out and when the crowds were all gone," Swift said. "So I want to thank my boyfriend, Adam, for that and I love you guys so much."
The two recently celebrated their one-year anniversary with a beach vacation, where they snapped photos of each other and carved their initials in the sand.
Prior to her relationship with Harris, Swift dated Harry Styles, Conor Kennedy, Jake Gyllenhaal and Joe Jonas. Harris was previously linked to Rita Ora, Aarika Wolf and model Anne V.
The Huffington Post has reached out to reps for Swift and Harris and will update this post accordingly.