Can cockatiels eat grapes?

Yes, in small amounts

Yes, in small amounts. Grapes are listed as suitable for pet birds by veterinary sources, but they are high in sugar, so cockatiels should only have a small piece now and then.

Portion: Half a seedless grape, cut into pieces
How often: Once or twice a week
Sugar: 15.5 g / 100 g

How to serve it

Wash thoroughly
Remove any seeds
Halve or quarter the grape
Take away leftovers after a couple of hours

Why

Risks. The main issue is sugar. Grape toxicity is well known in dogs; it has not been reported in birds, but that uncertainty supports keeping amounts small.

Benefits. A piece of grape can be a handy training reward because most cockatiels like the taste.

Questions owners ask 1

My cockatiel ate a whole grape. Is that an emergency?

No poisoning from grapes has been documented in birds, so a single grape is not usually an emergency. Watch droppings and appetite, and call your vet if anything seems off.

Grapes: nutrition per 100 g

Water	80.5 g
Energy	69 kcal
Sugars	15.5 g
Fat	0.2 g
Protein	0.7 g
Fibre	0.9 g
Calcium	10 mg
Phosphorus	20 mg
Calcium : phosphorus	0.5 : 1
Sodium	2 mg
Vitamin A (RAE)	3 µg
Vitamin C	3.2 mg

“Grapes, red or green (European type, such as Thompson seedless), raw”, USDA FoodData Central (SR Legacy, FDC 174683). Public domain.

Sources & method 4

The sources below discuss grapes for cockatiels (or for pet birds generally). Confidence: medium. Rated on the JOMIZOO Feeding Scale; when good sources disagree we choose the more cautious level.