O-formylcefamandole is a cephalosporin compound having (R)-O-formylmandelamido and N-methylthiotetrazole side groups. It is used (as the sodium salt) as a progrug for cefamandole. It has a role as an antibacterial agent and a prodrug. It is a cephalosporin and a formate ester. It is functionally related to a cefamandole. It is a conjugate acid of an O-formylcefamandole(1-).