The Callitroideae is a subfamily of Cupressaceae that comprises eight exclusively Southern Hemisphere genera. These conifers occupy a diverse range of ecological habits including arid and rainforest ecosystems, and are typically trees or shrubs bearing woody seed cones with decussate to whorled ovuliferous complexes. The Cretaceous was likely a pivotal time of diversification for this group following the separation of Gondwana and Laurasia. However, the Cretaceous record of Callitroideae is sparse and is known from a single occurrence in Australia. Most Callitroideae fossils are vegetative, assigned to modern genera, and are found in the Cenozoic of Australia, Tasmania, and South America. Thus, the distribution and diversity of Callitroideae during the Mesozoic are poorly understood. Herein, we characterize callitroid seed cones from the Late Cretaceous of Antarctica. There are two seed cones attached to vegetive shoots permineralized within a calcium carbonate concretion from the Santa Marta Formation, Beta Member (Campanian; 83-72 Ma) of James Ross Island, Antarctica. The seed cones measure ca. 1.7–2.0 mm in diameter and ca. 3.3 mm in length and consist of two alternating whorls of three ovuliferous complexes, which are keeled and ovoid-spatulate in shape. These ovuliferous complexes are composed of parenchymatous tissues, a uniseriate hypodermis, and one central resin canal. An elongate trilobed columella, ca. 2.4 mm in length, is present at the cone’s center. Between the larger ovuliferous complexes and the columella are several scale-like structures that are thin and composed of collapsed cells. We interpret these structures as vestigial ovuliferous complexes similar to what is seen in ovulate cones of Fitzroya. The cones are subtended by several transition scales and a vegetative shoot with tricussate awl-shaped leaves that are triangular in cross-section and have decurrent leaf bases. These Antarctic fossils have diagnostic characters of the Callitroideae, such as valvate ovuliferous complexes, a columella, and tricussate phyllotaxis, and share similarities with Fitzroya and Callitris. The unique combination of characters of the new fossils indicates they belong to a new genus. These Antarctic fossils add to a depauperate Cretaceous record of Callitroideae and provide additional evidence that these conifers were present in Antarctica, which was an important corridor for Gondwanan floras during the Late Cretaceous.