This systematic review of executive function (EF) interventions is the largest such review thus far, including 179 studies from all over the world, reported in 193 papers. It covers all the ways that have been tried to improve EFs, including computerized and noncomputerized cognitive training, neurofeedback, school programs, physical activities, mindfulness practices, and miscellaneous approaches (e.g., drama and Experience Corps), at all ages. A little studied approach—mindfulness practices involving movement (such as taekwondo and t’ai chi)—shows the best results for improving EFs. Promising school programs are second. Both approaches show better results than any cognitive training. Third best at improving EFs is noncomputerized cognitive training. Perhaps these three approaches show better results than computerized training because they involve more in-person trainer-trainee interaction. The best-performing computerized cognitive-training method for improving EFs is Cogmed®. Support was lacking for claims that N-back training improves fluid intelligence. Resistance training and “plain” aerobic-exercise interventions (e.g., running or walking) show the least evidence of benefit to EFs of all methods. Results for aerobic exercise with more cognitive or motor-skill challenges are only slightly better. This probably reflects how physical-activity interventions have been structured, rather than that physical activity does not benefit EFs. For any intervention, trainers’ ability to make the training activity enjoyable and to communicate their unwavering faith in participants and the program plus the activity being personally meaningful and relevant, inspiring commitment and emotional investment in participants to the activity and to one another is probably what is most important.