Although many children adopted internationally show remarkable recovery once placed in families, as a group they continue to exhibit persisting developmental deficits and delays in self-regulation. The current study uses a stratified, randomized, controlled trial to evaluate the effects of mindfulness-based and executive function trainings (EFTs) on internationally adopted (IA) children's self-regulation, including effortful/inhibitory control, attention, delay of gratification, and emotion-regulation. IA children ages 6–10 years were randomized into mindfulness training (MT), EFT, or no intervention (NI) groups. The MT and EFT groups attended 12 one-hour group sessions. Ninety-six children (MT, n = 33; EFT, n = 32; NI, n = 31) completed the study and were tested on computerized and non-computerized measures of self-regulation. Compared with the NI group, the MT group improved delay of gratification, and the EFT group improved inhibitory control and selective attention. There was no effect of either intervention on emotion regulation. MTs and EFTs show promise for improving self-regulation in IA children.