The purpose of this study was to investigate the oral health-related quality of life and type-D personality in cleft lip/palate (CLP) patients and the relationship between type-D personality and oral health-related quality of life (OHRQoL) in CLP patients. Fifty patients with CLP within age range from 8 to 15 years were chosen and asked to complete both Child Oral Health Impact Profile (COHI) and Type-D scale (DS14) questionnaire. Moreover, the participants of a control group matched with CLP patients were asked to complete the DS14 questionnaire. A significant difference between boys and girls on the subscale “emotional well-being” of COHIP (P = 0.001) and a positive significant correlation between “oral symptoms” and age (P = 0.029) were found among CLP patients. The prevalence of type-D personality was equal between clefts and nonclefts groups. However, there was a significant relationship between type-D personality and OHRQoL in CLP patients regarding mean scores of overall COHIP and its subscales (P < 0.05). This study has shown that the personality type remains unchanged among cleft patients and a meaningful relationship exists between type-D personality and OHRQoL.