Onion (Allium cepa L.) is a spice crop and a valuable economic crop cultivated in a variety of environments around the world. Because of its export demand, it is extremely important in terms of foreign exchange. Drought stress, waterlogging stress, heat stress, cold stress, and salinity stress all have an impact on onion growth, production, and yield in different ways. A lack of water causes low productivity, therefore to increase onion yield, a constant supply of water is needed. Onions are particularly susceptible to salt stress. The number of bulbs per unit area, height, and fresh weight of onion bulbs, are all affected by salinity in irrigation water. It has an effect on bulbing and the quality of harvested bulbs. Waterlogging has a major effect on bulb development and yield at various growth stages. Waterlogging stress in onions may prevent moving from source to sink, lowering bulb yield. The possible flavor of onions can be affected by the surrounding climate. The bulbing response is influenced by temperature, and the degree to which it is influenced varies by variety. As the temperature increases, the number of leaves decreases. The bulb diameter, bulb weight, and bulbing index (bulb/neck diameter) all increase as the temperature rises. This review provides an in-depth description of the effect of abiotic stress on onion yield.