Teachers across New Jersey (NJ) are advancing within the profession as teacher leaders. The problem addressed in this study is that there is a gap in knowledge regarding what goals and mindsets motivate NJ teachers to engage in teacher leadership (TL) and seek formal teacher leader credentials. The purpose of this quantitative study was to explore the relationship between teachers' work goal orientation (WGO) and the mindset measure kind of person (KOP) as well as understand how these variables predict aspiration to engage in TL and highest aspiration for a formal teacher leader credential. The goal orientation theory was used for this correlational study, where NJ teachers were invited through purposive sampling (n = 112) to take Brett and Vandewalle's WGO instrument and Dweck's KOP implicit theory scale. This study involved exploring whether WGO learning, proving, avoiding, and KOP scores predict aspiration to engage in TL; binomial logistic regression analysis showed for every increase in the mean of WGO learning score, participants were 4.663 more likely to aspire to engage in TL. This study also involved exploring whether WGO learning, proving, avoiding, and KOP scores predict highest aspiration for a formal teacher leader credential; ordinal logistic regression analysis showed for just one mean score increase in WGO learning score, the probability of aspiring to earn a formalized teacher leader credential increases 2.591 times. Positive social change may result if teachers with a WGO learning goal orientation (LGO) are attracted and retained into the profession through teacher leadership opportunities and training. [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.]