A long-range strike from David Turnbull in the 15th minute proved the difference between the sides in a largely dull affair at Parkhead that lacked excitement.
The result saw Neil Lennon’s side close the gap on Rangers at the top of the table to 15 points with the two clubs now having played the same number of games (29).
Here's how the Celtic players rated:
1. Scott Bain - 7
Fantastic pass out of defence helped split Aberdeen midfield open for first goal. Saved an effort from Hornby that was straight at him and made a brave catch in the last minute. Photo: Craig Williamson - SNS Group
2. Jonjoe Kenny - 7
Comfortable in possession and showed good awareness to cover for Ajer and deny Aberdeen a chance after the centre-half was pulled out of position. Photo: Ross MacDonald - SNS Group
3. Kristoffer Ajer - 8
Dominant in the air and on the deck. Marshalled the defence like a veteran. Excellent performance. Photo: Craig Foy - SNS Group
4. Stephen Welsh - 7
The young centre-back defended well on his return from injury. Showed he deserved to win his place straight back from Shane Duffy. Photo: Ross Parker - SNS Group