The observed baryon asymmetry of the Universe requires new sources of charge-parity ( \( \mathcal{CP} \) ) violation beyond those in the Standard Model. In this work, we investigate \( \mathcal{CP} \) -violating effects in the top-Higgs sector using the Standard Model Effective Field Theory (SMEFT) framework. Focusing on top-pair production in association with a Higgs boson and single top-Higgs associated production at the LHC, we study \( \mathcal{CP} \) violation in the top-Higgs Yukawa coupling and other Higgs and top interactions entering these processes. By analysing \( \mathcal{CP} \) -sensitive differential observables and asymmetries, we provide direct constraints on \( \mathcal{CP} \) -violating interactions in the top-Higgs sector. Our analysis demonstrates how combining \( t\overline{t}h \) and thj production can disentangle the real and imaginary components of the top-Yukawa coupling, offering valuable insights into potential sources of \( \mathcal{CP} \) violation. The sensitivity of these observables to SMEFT operators provides model-independent constraints on the parameter space, advancing the search for new physics in the top-Higgs sector.
