How do the Catholic Schools Consultants through their leadership and relationship with Principals influence the outcomes of Catholic systemic schools in New South Wales (NSW)? This research question has been of considerable interest to the professional communities of Catholic educators. Throughout NSW there are eleven diocesan Catholic school systems, each led by a Director assisted by senior field officers called Consultants, the equivalent position of Area superintendents or inspectors in other school systems. The leadership of these Consultants is considered critical for the effectiveness of the school systems especially through their influence on and with Principals. Within this survey research study, the total population of Consultants and Principals was invited to participate, and 45 Consultants (90%) and 365 Principals (76%) responded. The research study was based on the assumption that a ‘classical’ view of leadership should be augmented by a more complex, interactive view of leadership as relationship that influenced outcomes in school systems. The study was operationalized in three dimensions. Leadership was described by ten variables, derived from Sashkin’s (1998) Visionary Leadership Theory. The relationship between Consultant and Principals was posited as a composite of two variables, Interpersonal Relation and Shared Catholic Leadership Mindset, that are viewed as explanatory, mediating variables. Three selected outcome variables are posited – Educational Outcomes, School Outcomes and Spiritual Outcomes. The fifteen variables so described were developed and/or validated for this study using confirmatory factor analysis. Additionally, the impact of three demographic background factors of gender, school type, and years of networking association between Consultant and Principals on the main variables in the study was examined. A mediated – effects survey research design was used. Survey questionnaires were sent from the local Catholic Education Office to each volunteer Consultant and to her/his associated network of Principals on a confidential basis and returned directly to the researcher. At no stage did the researcher know the identity of the respondents. Data analysis methods included comparative means analysis of Consultants’ and Principals’ perceptions of the variables; multiple regression analysis and structural equation modelling to examine the associations between variables; MANOVA analysis to examine demographic background factors; and finally some descriptive analysis of survey data to provide validation or further insights. The study results showed that both Consultants and Principals agreed that the Consultants demonstrated visionary leadership as defined by Sashkin (1998) although there were significant differences on seven leadership factors. There was high level agreement that Consultants and Principals exhibited a shared mindset, described as Shared Catholic Leadership Mindset, and outstanding interpersonal relationships. Findings about the associations between variables showed different results for Principals and Consultants. The ‘Principals’ model suggested that the two relationship variables acted as mediators between some of the ten leadership variables and the three outcome variables. On the other hand, the ‘Consultants’ model suggested that neither of the two relationship variables acted as mediators, but that only two leadership variables, Capable Management and Creative Leadership, had any influence on Outcomes. There were no significant differences on results due to gender, school type or years of networking association for either Principals or Consultants. These results, supplemented by qualitative findings, led to the conclusion that there was a need for system policy makers to reconceptualise the leadership of such Consultants to emphasise the importance of the shared mindset, and the synergistic element in the relationship between Consultant and Principals. There was a recommendation that further research replicate this study with other Catholic, Government and independent education systems. The use of structural equation modelling analysis in similar future research was also recommended.