Organizer (noun)

1. One who arranges or puts things in order.
2. A person who plans and coordinates events or activities.

Origin:

From organize +‎ -er.

Examples:

1. The closet organizer helped to arrange my clothes and shoes.
2. The event organizer did an excellent job planning the charity fundraiser.
3. The conference organizer ensured that all the speakers and attendees had the necessary equipment and materials.
4. The union organizer worked to recruit new members and negotiate better working conditions.
5. The party organizer hired a caterer and DJ for the celebration.