OBJECTIVE To develop and validate new measures of diabetes-specific health-related quality of life (HRQOL) for people with type 1 diabetes (T1D) that are brief, developmentally appropriate, and usable in clinical research and care. Here we report on the phases of developing and validating the self-report Type 1 Diabetes and Life (T1DAL) measures for children (age 8-11) and adolescents (age 12-17). METHODS Measure development included qualitative interviews with youth and parents (n = 16 dyads) followed by piloting draft measures and conducting cognitive debriefing with youth (n = 9) to refine the measures. To evaluate the psychometric properties, children (n = 194) and adolescents (n = 257) at three T1D Exchange Clinic Network sites completed the age-appropriate T1DAL measure and previously validated questionnaires measuring related constructs. Using psychometric data, the investigators reduced the length of each T1DAL measure to 21 and 23 items, respectively, and conducted a final round of cognitive debriefing with six children and adolescents. RESULTS The T1DAL measures for children and adolescents demonstrated good internal consistency (α = 0.84 and 0.89, respectively) and test-retest reliability (r = 0.78 and 0.80, respectively). Significant correlations between the T1DAL scores and measures of general quality of life, generic and diabetes-specific HRQOL, diabetes burden, and diabetes strengths demonstrated construct validity. Correlations with measures of self-management (child and adolescent) and glycemic control (adolescent only) demonstrated criterion validity. Factor analyses indicated four developmentally specific subscales per measure. Participants reported satisfaction with the measures. CONCLUSIONS The new T1DAL measures for children and adolescents with T1D are reliable, valid, and suitable for use in care settings and clinical research.