Can you become a police officer with only one kidney?

Solitary Kidney: It depends on your department's policy but I don't see why not. Those with one kidney, barring any other health issue or genetic predisposition, can live perfectly normal lives. You just need to be careful to not expose your kidney to harm- i.e. specific meds or surgeries.

Not always: "Some branches of military service, police and fire departments will not accept individuals with only one kidney. In addition, if you are already in military service, certain new service career options may not be available to you." REF: https://www.kidney.org/transplantation/livingdonors/making-decision-to-donate