Beard oil is a type of beard conditioner that is considered beneficial to growing and maintaining all types of beards. These oils generally contain natural ingredients, such as jojoba or sesame seed oil, which are considered easily absorbed by the skin and hair. Beard oil may also contain various nutrients considered helpful for maintaining the beard's healthful appearance, such as vitamin E. Essential oils may be added to beard oil to give it a pleasant aroma. Rosemary, bay, cedar wood, and lime essential oils are popular fragrances for beard conditioning oils. Applying beard conditioner to the beard after washing is believed to moisturize the skin and hair, preventing facial dandruff and itching, and it's also believed to help control unmanageable beard hairs and soften the texture of the beard.

Natural oils such as jojoba and sesame seed oil may be the most popular main ingredients for beard oils. These oils are chemically similar in composition to the natural oils produced by the sebaceous glands of the skin. As a result, the skin and hair may absorb these oils more easily than others. Beard hair, being generally more coarse than head hair, typically benefits most from the opportunity to absorb pure oils, rather than from the use of conditioners intended for head hair. The oils used in beard oil often have anti-inflammatory properties, which can help to cut down on the irritation and itching that occurs with many beards.

Oils for the beard need not necessarily be scented, but most are. The scents used in most types of beard oil are typically those considered masculine in nature, such as coriander, lime, peppercorn, or sandalwood. Some types of beard oil are intended merely to add fragrance to the beard, and are largely worn as a type of cologne. Most types, however, will have some conditioning benefits for the beard hair, even if they are not specifically formulated as beard conditioners.

A well-groomed beard is generally considered more comfortable and more visually appealing than a poorly groomed one. Beards should generally be shampooed and dried carefully with each shower or bath. Most barbers recommend carefully massaging shampoo into the beard with the fingertips, all the way down to the skin, to make sure dirt, debris and perspiration are washed away. Careful towel-drying of the beard can prevent split ends and help maintain the beard's smooth appearance. Beard oil should generally be applied as a final step, to condition the beard and giving it a soft, luminous appearance.