The singer, 21, had previously said he wanted to "move on" from the N-word posts that saw him talk about "light-skinned girls."
But after backlash, Shawn has now told fans he "wholeheartedly apologizes."
Writing on Instagram, Shawn said: "I posted some racially insensitive comments on social media when I was younger and I am so sorry.
"I apologize wholeheartedly for what was said and understand how offensive those posts were.
"There is no place for comments like that and those words do not represent who I am. I stand for complete exclusivity, equality and love."
In the now-deleted tweets, Shawn appears to refer to a friend writing: "A regular day with m n**** kareem[sic]"
Another reads "light-skinned girls>>."
In another he posts a selfie with his hair sticking up along with the caption: "I have an AFRO!"
In a Q&A with an upset fan who quizzed him about the tweets, Shawn said:"A lot of things just need to be moved on from, but I also think that the things that [you] saw, like I had friends when I was 14 who would like take my phone and post things of them because they thought it was funny that I had like 2,000 followers and it was this big thing.
"They’d post photos of themselves and at the time I was just like not thinking about it.
"I had no idea I was going to have 50 million followers, which doesn't make it any better.
"But yeah totally I apologize for everything insensitive I said in the past, but with that being said, yeah, I think that’s not my personality."
Shawn is now dating Camila Cabello after their racy music track "Senorita."
They're set to perform for the first time together since confirming their romance at the VMAs next week.
This article originally appeared in The Sun.