Olax viridis Oliv. (Olacaceae) is a shrub common in the tropics and grows well in the forest and savannah region. Species of this genus are used traditionally in the treatment of breast cancer and related diseases among others. This study aims to report the antiproliferative and in vitro antioxidant activities of butanol fraction of O. viridis root bark. Extraction of the pulverized dry bark was done by cold maceration using methanol and was further partitioned successively with N-hexane, dichloromethane, ethyl acetate and n-butanol. Fractionation of butanol fraction was done with vacuum-liquid-chromatography and subfractions monitored with TLC. Phytochemical screening of fraction A-C was carried out using standard phytochemical method while their constituents were evaluated using TLC. Antiproliferative activity was determined by cell viability assay using Saccharomyces cerevisae (yeast) as a model organism while the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay was used for antioxidant evaluation in-vitro with ascorbic acid as the reference standard for comparison. All the sub-fractions contain sugar, steroids, triterpenes and saponins. Sub-fractions A, B and C showed constituents (Rf values of 0.23, 0.41, 0.51 and 0.58), (Rf values of 0.46 and 0.63) and (Rf values of 0.44 and 0.62) respectively. The sub-fraction A showed dose-dependent activities for DPPH radical scavenging activity thus A(IC50=1.60mg/ml) while antiproliferative activities of all the sub-fractions were dose dependent A(IC50=8.22mg/ml) >B( IC50=>10 mg/ml). Sub fraction A showed a promising activity, and this preliminary study validated the traditional use of Olax species in the treatment of cancer.