Buy it from the man in Floaroma Meadow.
Find it on the ground. There's some here and there.
Combee's ability. If Combee has no held item going into a battle, then the battle sometimes ends with Combee holding honey.
More specifically you can find it on the ground at Route 205 (With Dowsing Machine), Route 208, Route 214 (With Dowsing Machine), Route 215 (With Dowsing Machine), Eterna Forest, and Solaceon Town.
Hope I helped! :)