Ceftazidime, sold under the brand names Fortaz and Tazicef, is an antibiotic useful for the treatment of a number of bacterial infections. It is a third-generation cephalosporin.

As a class, cephalosporins have activity against Gram-positive and Gram-negative bacteria. The balance of activity tips toward Gram-positive organisms for earlier generations; later generations of cephalosporins have more Gram-negative coverage. Ceftazidime is one of the few in this class with activity against Pseudomonas. It is not active against methicillin-resistant Staphylococcus aureus.