Employee support is a key factor in creating more welcoming and accepting work environments for lesbian, gay, bisexual, and transgender (LGBT) individuals in sport. As such, organizations need to understand what factors encourage employees to display attitudes and behaviors that support inclusion. Thus, the purpose of my dissertation was to advance the literature by examining antecedents and outcomes related to employee support for LGBT inclusion and equality in the workplace. In Study 1, I provide LGBT employees the opportunity to share their perceptions of support for LGBT inclusion, particularly how the attitudes and behaviors of their coworkers foster or inhibit acceptance in the workplace. Results indicate that various micro-level (demographics, personality, experiences with LGBT individuals) and meso-level factors (organizational culture for diversity, support of relevant others) influenced the level of employee support for LGBT inclusive policies. Furthermore, power meaningfully influenced these dynamics, such that individuals in low status positions within the athletic department were hesitant to show support for LGBT equality. However, those who did champion LGBT inclusive initiatives successfully modeled supportive behaviors and positive attitudes toward LGBT individuals, vocally opposed discriminatory treatment, and provided sexual minorities with a safe space at work. In Study 2, I develop a multilevel model that addresses factors at the macro-level (i.e., mass media, inclusive community), meso-level (i.e., sexual orientation diversity, presence of other allies), and micro-level (i.e., personality, personal values, attitudes toward LGBT individuals, contact with LGBT individuals) that influence ally support. In addition, I differentiate between attitudinal and behavioral support for LGBT equality, and discuss various factors that may encourage allies to engage in more active ally behaviors. In Study 3, I drew from the multilevel model to examine how micro-, meso-, and macro-level factors influence attitudinal support for sexual LGBT inclusion among sport employees, and determine if these attitudes affect behavioral support for LGBT inclusion in the workplace. The results from the study offered support that multilevel factors relate to support for LGBT inclusion. Specifically, sex, supervisor support, and typed of media consumed were related to attitudinal support for LGBT inclusion, and these attitudes positively associated with championing behaviors.