The singer hadn't tweeted since 18 March before today's message thanking fans for their support over the past few weeks.
Zayn said: "Wanna say thanks to everyone that's been there for me over the last few weeks. Love you all… you know who you are x."
He then clarified: "The x is a kiss by the way. Ha. It's not a mystery. Sorry to any confused."
(Anyone else notice he still hasn't changed the One Direction music link in his bio?!)
Zayn hadn't been on his Twitter account since March, when he tweeted his love for Little Mix fiancée Perrie Edwards after photos emerged of him holding hands with another woman while on the other side of the world.
He had said: "I'm 22 years old... I love a girl named Perrie Edwards. And there's a lot of jealous f**ks in this world I'm sorry for what it looks like x
Since then, a LOT has changed in Zayn's world…
First came the news he was leaving the One Direction world tour after being signed off with stress, then the bombshell that he had quit the band after five years in the spotlight.
Next, we learned he had been working with Naughty Boy in the recording studio, suggesting a solo career could be happening. Then, over the weekend, he made his first public appearance since leaving 1D, attending the Asian Awards in London sporting a new buzz cut hairdo.
So. Much. Change.
Watch the public - and some celebs! - react to Zayn's exit: