Petty officer, 1st class, PO1, is a Naval non-commissioned member rank of the Canadian Forces.

The rank insignia of the PO1 is a crown worn on both forearms of the Service Dress tunic, and on slip-ons on both shoulders of other uniforms.

The full appellation "Petty Officer 1st-Class" or "PO1" in speech is generally used only when the "first-class" distinction be made, such as to distinguish between members with similar names but differing ranks, or on promotion parades.

It is common practice to refer to the Petty Officer by this shorthand in all but the most formal correspondence (such as printing and inscription on awards).

Once the examination is complete, a quota is established based upon the needs of the Navy with respect to the specific rating the sailor holds.

On white uniforms, the eagle, rating, and chevrons are dark blue (almost black- this has led to the eagle being referred to as the "crow" in common practice, and often the entire rating badge is simply referred to as the crow).

On navy blue (black) uniforms, the eagle and rating are white, and the chevrons are red, unless the sailor has served in the Navy for at least 12 consecutive years, with good conduct, then that sailor wears gold chevrons on the dress blue uniform.

Gold chevrons are also worn on the collars of the Navy blue coveralls uniform, and on the black garrison cap (only) worn with the Navy service working uniform (often called "peanut butters" or "black and tans").

There are situations when there are more than one first class petty officers in a division, due to the demands for highly experienced or skilled Sailors in technical areas.