Although omalizumab (anti‐IgE) is currently only approved for the treatment of asthma and chronic idiopathic urticaria, it has also been studied as an off‐label treatment for numerous allergic conditions, including use as an adjunct to allergen immunotherapy in the treatment of allergic rhinitis, asthma, venom hypersensitivity and food allergy. We conducted a review of publications involving the use of omalizumab with allergen immunotherapy, by searching PubMed with key search terms of “omalizumab” and “immunotherapy.” Omalizumab has been used in combination with inhalant allergen immunotherapy for the treatment of seasonal allergic rhinitis and comorbid asthma. While there have been no randomized controlled trials evaluating the addition of omalizumab to venom IT, several case reports and small patient series have been published on the use of omalizumab with venom IT. Omalizumab has been used in conjunction with oral immunotherapy for the treatment of milk, peanut and egg, as well as other foods in multi‐allergen protocols. In conclusion, omalizumab used in conjunction with immunotherapy has shown promising results, especially in the reduction of adverse reactions. At this stage, larger, randomized, placebo‐controlled trials are needed to better identify those patients who would benefit the most from the addition of omalizumab to immunotherapy, as well as optimal dosing strategies and duration of treatment.