Abstract: Lorentz symmetry posits that the laws of physics are invariant regardless of the orientation and velocity of the reference frame in which they are measured. Violation of this symmetry can be quantified using the Standard-Model Extension (SME) framework, which predicts the effects that Lorentz violation would have on elementary particles and their interactions. This model predicts a dependence of the production cross section for top and antitop quark pairs on sidereal time as the orientation of the experiment changes with the rotation of the Earth. In this talk I will present the results of a search for Lorentz violation in ttI,, events using data collected with the D0 detector at the Fermilab Tevatron Collider, setting upper limits on parameters within the SME describing the possible strength of Lorentz violation in the top sector. I will also investigate the prospects for extending this analysis using the ATLAS detector at the Large Hadron Collider which, because of the higher rate of top-antitop events at that experiment, has the potential to improve the limits determined at D0.