A door for a thrust reverser of a nacelle of an aircraft being pivotally amounted on a fixed structure of the nacelle, in particular, the door being fitted with deflectors deflecting air flow is disclosed. The deflectors are arranged at an upstream end of the door and mounted such that they can move in a deflection plane perpendicular to the plane of the door. Each deflector is associated at its ends with an articulation arm capable of rotating about a pivot axis perpendicular to the deflection plane, allowing the deflectors to move in a straight line in the deflection plane. The present disclosure also relates to a thrust reverser system including the door and a fixed structure on which the door is pivotally mounted between a closing position and an open position.