Although everybody learns at their own pace, the traditional, standardized education system remains prevalent. Unfortunately, this traditional system does not meet all learner needs and results in low academic achievement as demonstrated by state and national standardized tests (Netcoh, 2017; Pennsylvania Department of Education, 2019c; Schwahn & McGarvey, 2012; Serino, 2017). Personalized learning is a method of instruction that has the potential of improving the educational system (Bingham, 2017; Bingham, Pane, Steiner, & Hamilton, 2018). Despite research that shows personalized learning can be beneficial and lead to better learning (Prain et al., 2013), it is unclear if personalized learning also leads to improved student achievement and growth in mathematics. A clearer understanding of this can benefit students and educators as improved methodology could be indicated. This study looked to examine the relationship between the use of personalized learning and student mathematical achievement and student mathematical growth. The study also looked at key differences between student mathematical achievement and student mathematical growth in schools using personalized learning approaches and those using traditional learning models. There was a very weak, negative relationship between the use of personalized learning and student mathematical achievement and a weak, negative relationship between the use of personalized learning and student mathematical growth. The difference between student mathematical achievement in personalized learning schools and traditional learning schools were varied. The study showed differences between the student mathematical growth of students in personalized learning schools and traditional learning schools with traditional learning schools demonstrating greater growth. [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://www.proquest.com/en-US/products/dissertations/individuals.shtml.]