Students’ well-being is influenced by the Indoor Environmental Quality (IEQ) of classrooms. Poor IEQ, particularly inadequate acoustic conditions, can negatively affect students’ learning performance and comfort. This study aims to identify indoor environmental conditions that promote students’ multi-domain comfort in classrooms. Field campaigns were conducted in various primary schools in Northeast Italy, where physical parameters related to the four main comfort domains—namely sound pressure level, CO2 concentration, air temperature, and horizontal illuminance—were measured during the administration of a right-here right-now questionnaire to gather their sensation regarding the acoustic, thermal, visual, and indoor air quality environments. Prior to the study, all participants underwent a comprehensive hearing screening to eliminate any potential biases related to auditory impairments. Subjective responses under different indoor conditions were analyzed to explore possible correlations between indoor parameters and students’ multi-domain sensation.