Background/Context: Implicit bias, or stereotypes and attitudes that may or may not reflect known positions, has been implicated in teachers' disciplinary interactions with students; however not all of the differences in discipline severity by race are accounted for by teachers. School administrators have received little attention concerning implicit bias, although they are involved in the decision-making process that determines disciplinary outcomes. Purpose: The present study sought to explore the influence of school principals' and assistant principals' implicit biases on the severity of discipline experienced by students of different races (evaluated using perceived racial stereotypicality). Participants: Pennsylvania schools with at least 10 reported incidences of exclusionary discipline and 10-90% students of Color were invited to participate in this study, with a resulting sample of 43 administrators representing 22 schools nested in 7 school districts, accounting for 3,898 unique student behavioral incidents. Research Design: This study employed a non-experimental, cross-sectional quantitative design using both collected and extent datasets. Data Collection and Analysis: Student behavioral data and resulting outcomes were collected from schools using extant, student-blinded datasets and coded for analysis. Data on administrators' implicit bias and demographics was collected via a short survey and online completion of the Implicit Association Test for Race. The data was analyzed separately for objective and subjective discipline decision-types, using hierarchical linear modeling. Findings: The study yielded three major findings: (1) school administrators held pro-White implicit biases; (2) administrators' implicit bias accounted for differences in discipline severity by student race only for subjective discipline decision-types; and (3) student race accounted for some of the differences in objective discipline decisions. Conclusions/Recommendations: Implicit-bias remediation efforts in schools should be extended to school administrators involved in discipline decisions, and school policies must be evaluated for bias. Research should extend this study to increase sample size and district inclusion so that district-level differences are examined and evaluated for policy-level biases.