We study quasinormal modes (QNMs) for the Klein-Gordon equation on Reissner-Nordström-de Sitter black holes with near-extremal charge. We locate all QNMs of size \mathcal{O}(\kappa_{\rm C}) where \kappa_{\rm C} is the surface gravity of the Cauchy horizon (which vanishes at extremality): they are well-approximated by \kappa_{\rm C} times QNMs of the near-horizon geometry {\rm AdS}^2\times{\mathbb S}^2 of the extremal limit.
