Yes, but only in moderation as pineapples contain a lot of sugar and giving too much of this fruit to your rabbit could cause health issues such as digestive problems, cause obesity and possibly cause diabetes. Make sure rabbits only get pineapple as a rare treat.
As mentioned above pineapple along with many other fruits contain a large amount of sugar which in generally bad for most animals and even humans to eat. Therefore you need to moderate how much a bunny eats.
Ideally a rabbit should be eating such things as fresh timothy hay, fresh water and rabbit pellets to keep themselves healthy and have a well balanced diet.
These things they should be eating on a daily basis and fruits should be kept to a minimum.
If you are unsure of what your rabbit can and cannot eat it is best to contain a veterinarian or a local pet shop employee to get more details on what a rabbit can and cannot eat.
Can I feed pineapple to my rabbit? Yes, but only in moderation as a treat.
Make sure to remove all out the outer skin and leaves and give them only a few small chunks. Avoid giving them too much as its bad for their health and make sure the pieces are small so that they are not a choking hazard.