Objective. The diabetes device confidence scale (DDCS) is a new scale designed to evaluate school nurse confidence with diabetes devices. We hypothesized that the DDCS score would be associated with related constructs of school nurse diabetes knowledge, experience, and training. Research Design and Methods. In a cross-sectional study, we coadministered the DDCS and diabetes knowledge test 2 (DKT2) questionnaires to school nurses in Pennsylvania. We summarized DDCS scores (range 1–5) descriptively. We evaluated the relationship between the DKT2 percent score and DDCS mean score with the Spearman correlation coefficient. Simple linear regression examined school nurse characteristics as predictors of DDCS score. Results. A total of 271 completed surveys were received. The mean DDCS score was 3.16 ± 0.94, indicating moderate confidence with devices overall. School nurses frequently reported low confidence in items representing specific skills, including suspending insulin delivery (40%), giving a manual bolus (42%), knowing when to calibrate a continuous glucose monitor (48%), changing an insulin pump site (54%), and setting a temporary basal rate (58%). The mean DKT2 score was 89.5 ± 0.1%, which was weakly but not significantly correlated with the DDCS score (r = 0.12,
p
=
0.06
). Formal device training (
p
<
0.001
), assisting ≥5 students with diabetes devices in the past 5 years (
p
<
0.01
), and a student caseload between 1000 and 1500 students (
p
<
0.001
) were associated with higher mean DDCS score. Conclusions. DDCS score is related to prior training and experience, providing evidence for the scale’s convergent validity. The DDCS may be a useful tool for assessing school nurse readiness to use devices and identify areas to enhance knowledge and practical skills.