The pop hunk met with fans outside the city's Radisson Blu Hotel in Argyle Street on Wednesday and delighted his army of followers by posing for pictures.
One lucky One Direction fan Courtney Atkinson tweeted a picture with Zayn, and said: "I finally met my favourite @zaynmalik today and got pictures. Beyond happy!"
Zayn was in town to support fiancee Perrie Edwards whose band Little Mix played two nights at the city's Clyde Auditorium.
One Direction are due to open Radio 1 Big Weekend on Saturday at the Glasgow Green.
The Evening Times are gearing up for Radio 1's Big Weekend and we're planning special online coverage throughout the weekend, starting at midday on Friday and not finishing until midnight on Sunday.
Our festival team will be capturing all the colour from Britain's biggest free ticketed live music event, with 50,000 music lovers on hand to see such big names as One Direction, Paolo Nutini, Pharrell Williams and Katy Perry.
We'll have the latest backstage gossip from the stars and top DJs, and reaction from fans, and we've created our own hashtag we want you to share when you're telling the world about your #weegiebigweekend experiences.