The invention provides seed and plants of the onion line designated SV4522NB. The invention thus relates to the plants, seeds and tissue cultures of onion line SV4522NB, and to methods for producing an onion plant produced by crossing a plant of onion line SV4522NB with itself or with another onion plant, such as a plant of another line. The invention further relates to seeds and plants produced by such crossing. The invention further relates to parts of a plant of onion line SV4522NB, including the bulbs and gametes of such plants.
