Crowmarsh Rural District existed in Oxfordshire, England from 1894 to 1932.
It was created under the Local Government Act 1894 from the part of the Wallingford Rural Sanitary District that was in Oxfordshire. The remainder of the sanitary district was in Berkshire and became the Wallingford Rural District. Crowmarsh Rural District continued to be administered from Wallingford, with meetings held in the former workhouse in the town.
The district was abolished in 1932 under a County Review Order, being split between the existing Henley Rural District and the new Bullingdon Rural District. Since 1974 the entire area has been part of the District of South Oxfordshire, which also includes Wallingford and district. The boundaries between Oxfordshire and Berkshire were altered in 1974 making Wallingford part of Oxfordshire.