Can I Give My Cat Advil?

No
Cats are roughly twice as sensitive as dogs. No safe dose exists at any weight.
Source: Pet Poison Helpline
Already ingested? Pet Poison Helpline 855-764-7661

The safe habit

Confirm any medication decision with your veterinarian, who knows your cat's health history and other medications. VetDose shows published reference data, not prescriptions.

See also

Other danger (no safe home dose) questions for cats