Among the elements phosphorus (P), sulfur (S), chlorine (Cl), and fluorine (F), fluorine (F) has the least metallic character.
In general, metallic character decreases as you move from left to right across a period in the periodic table. Fluorine is located in Group 17 (the halogens) and is the most non-metallic element, while phosphorus and sulfur, which are further to the left, exhibit more metallic character than fluorine.