The black-and-white picture shows the Bieber donning a pair of round glasses as he appears to have a conversation with 'Ye and some other men, reported Ace Showbiz.
"Taylor swift what up," the 22-year-old singer wrote in the caption, prompting his fans and Swift's haters to flood her Instagram page with the same phrase.
Bieber is the latest A-lister weighing in on Swift's feud with West, which worsened last month after their phone conversation about the controversial lyrics on his "Famous" was leaked online by the rapper's wife Kim Kardashian.
Following the leak, she posted on Twitter, "There are more important things to talk about... Why can't people use their voice for something that matters? Truth is last thing we need right now is hate, in any form.