Bovine viral diarrhea virus 1 (BVDV-1) belongs to the genus Pestivirus within the family Flaviviridae. Based on the 5' untranslated region (UTR) sequence, BVDV-1 can be divided into at least 17 subtypes (1a though 1q). BVDV-1i is an uncommon subtype that has been reported in the United Kingdom and Uruguay. Here, we report the complete genome sequence of the first subtype 1i BVDV-1 (strain ACM/BR/2016) isolated from cattle in southern Brazil. The genome is 12,231 nt in length and contains a single ORF that encodes a polyprotein of 3,896 amino acids, flanked by 5' and 3'UTRs of 325 and 220 nt, respectively. Phylogenetic inferences based on the whole genome, the 5'UTR, and the Npro region showed that strain ACM/BR/2016 is closely related to previously characterized BVDV-1i members. Its 5'UTR shares the highest nucleotide identity (90.5%) with BVDV-1i strains from United Kingdom, and its Npro is most closely related to that of a Uruguayan strain (90.6%). To the best of our knowledge, this is the first BVDV-1i strain from which the whole genome has been completely sequenced and characterized. The complete genome of a BVDV-1i will help future studies on pestivirus evolution and heterogeneity.