The Mind-on-Breathing (MOB) intervention is a mindfulness-breathing exercise that aims to help promote student academic engagement (AE) and reduce off-task behaviors (OFT). MOB is designed from simple, shared technical features common to meditation, mindfulness, and breathing-related exercises that can be implemented in one-on-one settings with minimal training and no monetary cost. Using a multiple baseline design, the effects of MOB on student academic engagement and off-task behaviors were investigated with a sample of three 5th grade students. Systematic Direct Observation (SDO) was used to collect data on academic engagement and off-task behaviors using momentary time sampling and partial-recording, respectively. Results were interpreted using visual analysis as well as nonparametric effect size estimates (i.e., Percent of nonoverlapping data; PND; Scruggs, Mastrodieri, & Casto, 1987, Tau U; Parker, Vannest, Davis, & Sauber, 2011). Data suggested that MOB was effective for all three participants in increasing academic engagement and reducing off-task behaviors. Implications for interpreting results within a behavioral framework for implementation in a multitiered system of supports (MTSS) are provided. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]