Herein I present a comprehensive view of mentoring and professional development programs in science, technology, engineering, and mathematics (STEM) undergraduate education. In CHAPTER 1 I describe a brief outline of this dissertation. In CHAPTER 2 I present a meta-analysis and systematic review of undergraduate mentor programs, where I find an overall lack of consensus and high-quality research design among the literature, limiting the application of meta-analysis interpretation. In response, I developed and validated a tool, the STEM Mentoring Rubric (STEMMR), to align the research community with best practices in STEM undergraduate mentoring programs. I used multiple raters to validate the STEMMR, rooting its salient factors in the STEM mentoring literature. Next, I describe a series of quantitative and qualitative research studies I conducted on various learning groups in STEM education, including pre-service STEM teachers in CHAPTER 3, STEM undergraduates in an introductory chemistry course in CHAPTER 4, and STEM faculty teaching undergraduate food, energy, and water nexus courses in CHAPTER 5. CHAPTER 6 outlines a brief conclusion of this dissertation. Overall, I found that the emergent themes and results from these studies supported the findings from my meta-analysis and systematic review of STEM mentoring programs in CHAPTER 1 and contributed to the field of undergraduate STEM education. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]