Background: Speech is the most common method of communication. Video-based clinical communication evaluation is a requirement for children with speech-language impairments living in rural areas, and those who have limited mobility. Aims: To determine the validity and reliability of the Turkish version of the Viking Speech Scale (VSS-T) via live and video-based observation for children with cerebral palsy (CP) aged 4-18 years. Methods & Procedures: A total of 142 children (mean age 8.18 ± 3.98 years; 68 female) with CP were included in this study. Their motor, communication, visual and eating-drinking function levels and comorbidities (dental, swallowing, cognitive impairments and epilepsy) were recorded. The Intelligibility in Context Scale (ICS), the Pediatric Evaluation of Disability Inventory-Social Function (PEDI-SF), and the Functional Independence Measure for Children-Communication (WeeFIM-C) were assessed to examine the concurrent validity of the VSS-T. The interrater reliability of the VSS-T was analysed between parents, physical therapists, and speech and language therapists from live and video-based observation. Intra-rater reliability was calculated from ratings made from live and video-based observations taken 3 weeks apart. Outcomes & Results: The VSS-T was strongly related to the ICS (r = -0.830), PEDI-SF (r = -0.819), WeeFIM-C (r = -0.643), other functional classifications (r > 0.432), and the comorbidities (Cramer's V > 0.284, p < 0.001). Good to excellent interrater reliability (?w [greater than or equal to] 0.838) and intra-rater reliability (intraclass correlation coefficient (ICC) = 0.848-0.995) were found between parents and therapists. Conclusions & Implications: Speech and language therapists, physical therapists, and parents can use the VSS-T as a valid and reliable classification system to describe speech intelligibility of 4-18-year-old children with CP. Both live and video-based observations can be used to administer the VSS-T.