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<i>Theileria orientalis</i> Ikeda has caused an epidemic of bovine anemia and abortion across several U.S. states. This apicomplexan hemoparasite is transmitted by <i>Haemaphysalis longicornis</i> ticks; however, it is unknown if other North American ticks are competent vectors. Since the disease movement is largely determined by the host tick range(s), the prediction of the <i>T. orientalis</i> spread among U.S. cattle populations requires determination of additional competent tick vectors. Although <i>Rhipicephalus microplus</i> has mostly been eradicated from the U.S., outbreaks in populations occur frequently, and the U.S. remains at risk for reintroduction. Since <i>R. microplus</i> is a vector of <i>Theileria equi</i> and <i>T. orientalis</i> DNA has been detected in <i>R. microplus</i>, the goal of this study was to determine whether <i>R. microplus</i> is a competent vector of <i>T. orientalis</i>. Larval <i>R. microplus</i> were applied to a splenectomized, <i>T. orientalis</i> Ikeda-infected calf for parasite acquisition, removed as molted adults, and applied to two <i>T. orientalis</i> naïve, splenectomized calves for transmission. After 60 days, the naïve calves remained negative for <i>T. orientalis</i> by PCR and cytology. Additionally, <i>T. orientalis</i> was not detected in the salivary glands or larval progeny of acquisition-fed adults. These data suggest that <i>R. microplus</i> is not a competent vector of the U.S. <i>T. orientalis</i> Ikeda isolate.