Johan Bijnens Radiative and semileptonic decays in Chiral Perturbation Theory Abstract I give a short overview of what has been done in radiative and semileptonic Kaon decays in Chiral Perturbation Theory. This includes for semileptonic decays the work which has been done to order $p^6$ including preliminary results of isospin breaking to that order in $K_{\ell3}$. For the radiative decays I mainly present some results from recent work concerning $K_{\ell3\gamma}$. LU TP 07-21, arXiv:0707.0419 [hep-ph]