Antarctica played a central role in the assembly and distribution of Gondwanan plant lineages during the Late Cretaceous and Paleogene. This is particularly true for the subfamily Callitroideae (Cupressaceae). Today these conifers are important components of arid and rainforest environments and have a disjunct distribution across the Sourthern Hemisphere. Their extensive Cenozoic fossil record in Australia, South America, and Antarctica have made them an ideal study system for biogeographical studies. However, while molecular divergence time estimates indicate that crown-group Callitroideae originated and diversified by the Early Cretaceous, there has only been a single Cretaceous report (ovulate cones from Australia) to support this. Thus, the early evolution of these conifers is poorly understood. As part of an initiative to better understand Antarctica’s role in the evolution of Southern Hemisphere plant lineages, we report permineralized callitroid seed cones attached to an articulated branching system of leafy shoots from the Late Cretaceous of Antarctica. More specifically, the fossil was recovered from the Beta Member of the Santa Marta Formation, which is early Campanian (~80 Ma) in age and exposed on James Ross Island in West Antarctica. The cellulose acetate peel technique was used to prepare and study the specimen. In addition, a Bayesian total evidence phylogenetic analysis using five chloroplast loci and a preliminary morphological matrix of 35 characters was conducted to infer relationships of the fossil. The shoot branches at least four times and bears elongate leaves arranged in whorls of three. Leaves have a keel and midrib and are amphistomatic. Four ovulate cones terminating the ultimate shoots have been identified. Each cone is open and roughly discoid with six fertile cone scales arranged in alternating whorls of three. Cone scales are spathulate with a distal adaxial swelling. There is a conspicuous abaxial umbo near the tip of each cone scale. A conspicuous columella is present and all seeds have dispersed. In addition to the six fertile cone scales, there is an uppermost whorl of vestigial cone scales that are weakly developed and considerably smaller than the fertile ones. This combination of characters is diagnostic of the extant and monotypic Fitzroya, which is an ecologically important and emergent conifer restricted to temperate rainforests in Patagonia. Preliminary phylogenetic analysis recovers the Antarctic fossil as sister to Fitzroya; thus, we assign the fossil to the genus. The Antarctic Fitzroya differs from its extant counterpart by lacking resinous bodies in the vestigial cone scales and having a more robust columella. Our findings indicate that Fitzroya diverged from its sister genus Diselma well before their previously hypothesized Eocene-Oligocene divergence and supports a Cretaceous diversification for the Callitrioideae. Moreover, the  Fitzroya fossil characterized here (and an additional taxon from the same locality described at this conference) reveals that, by the Campanian, the callitroids were established in Antarctica, which was an important corridor for the distribution of Gondwanan plant lineages. This work provides valuable data for understanding the turnover and distribution of these ecologically important conifers in deep time.