No. Poppy seeds can be poisonous to cats. Its level of toxicity is from mild to moderate, depending on the amount ingested.
Common signs to watch for:
Inappetance
Sedation
Walking drunk
Coma
Slowed breathing
Slowed heart rate
Dilated pupils (cats)
The alkoloids found in poppies differ with each species; some can affect the central nervous system (e.g., brain). Ingestion of any part of the plant can result in sedation or an excited (e.g., euphoric) state.
See List of Pet Toxins for Cats and Dogs at Pet Poison Helpline.
Check out 5 Human Foods Cats Can Eat shared by Animal Planet.