Oil producing crops are plants that produce fixed or fatty oils in their seeds, which are used for consumption or for industrial purposes. These are so-called non-volatile oils which consist of glycerol and fatty acids, unlike volatile or essential oils (see there). These non-volatile oils are divided into drying oils which dry in the air and are used in the manufacture of paints and varnishes; semidrying oils, used for foods and soap manufacture; and non-drying oils which remain liquid and are used in the kitchen.
The oil is obtained by pressing the seeds, the residue is often used in cattle food.

Twelve crops are cultivated on large scale for fixed oil production (Oil producing plants 2; Oil producing plants 3). These are:
- sunflower, Helianthus annuus, the oil is used as frying oil and in margarine manufacture;
- rape, Brassica napus, rape oil is mainly used in margarine manufacture and as a lubricant in industry;
- castor-oil plant, Ricinus communis, castor oil is used in the manufacture of paints, soap and lubricants;
- maize, Zea mays, maize or corn oil is mainly used as cooking and salad oil and in margarine manufacture;
- peanut or ground nut, Arachis hypogaea, the oil is used as cooking and salad oil and in margarine manufacture;
- soybean, Glycine max, the soya oil is mainly used as cooking and salad oil and in margarine manufacture;
- flax, Linum usitatissimum, linseed oil is used in the manufacture of paints, varnishes, putty, and linoleum;
- cotton, Gossypium sp., cotton seed oil is used in foodstuffs;
- olive, Olea europaea, the oil is used as cooking and salad oil, the conservation of sardines, and in margarine manufacture (Oil producing plants 1);
- cocos palm, Cocos nucifera, cocos oil is used for the manufacture of margarine and soap;
- oil palm Elaeis guineensis, both palm oil and palm kernel oil are used for the manufacture of margarine and soap;
- sesame, Sesamum indicum, sesame oil is used as cooking and salad oil and in the manufacture of margarine and soap.

In two out of these twelve crops, the oil is only a by-product: maize and cotton. Maize is mainly a cereal, the oil is obtained from the squeezed germs. Cotton is a fibre crop, the seeds contain oil.

Other oil producing crops are the tung or mu-tree, Aleurites montana (see Ricinus communis) (A. montana 1); walnut, Juglans regia, and the opium poppy, Papaver somniferum. These oils are used in the preparation of paints and varnishes.
Nigerseed, Guizotia abyssinica; safflower, Carthamus tinctorius, and the horse-radish tree, Moringa oleifera, provide oils that are used for foodstuffs as well as in the manufacture of soap.
Croton, Croton tiglium (see Ricinus communis), produces croton oil, which is used medicinally.

A special plant is the African milkbush, Euphorbia tirucalli (see Ricinus communis). From its milk juice a motor fuel can be made, known as bio-petrol.