A hybrid sunflower, designated X4237, is disclosed. The invention relates to the seeds of hybrid sunflower X4237, to the plants of hybrid sunflower X4237 and to methods for producing a sunflower plant by crossing the cultivar X4237 with itself or another sunflower. The invention further relates to methods for producing a sunflower plant containing in its genetic material one or more transgenes and to the transgenic sunflower plants and plant parts produced by those methods and to methods for producing other hybrid sunflower derived from hybrid sunflower X4237.