To be a police officer do you have to use a firearm?

In most cases, yes. If the police in your area are armed then you would also be required to carry and qualify with firearms.

However, this is not always the case. In countries such as those within the United Kingdom, the standard police officers are unarmed, with only trained Authorised Firearms Officers ever carrying firearms.

This is occasionally true in the United States. For example, the Traffic Enforcement officers of the New York Police Department do not carry firearms.

Additional Information: the un-armed traffic enforcement officers referred to above, although uniformed, are CIVILIAN EMPLOYEES of the department. Their authority is much the same as school crossing guards. They are NOT sworn law enforcement officers and do not possess the power of arrest.