Aphasia, a language disturbance, frequently occurs following acquired brain impairment in adults. Because management of aphasia is often long-term, provision of ongoing and equitable access to treatment creates a significant challenge to speech-language pathologists (SLPs). This study aimed to determine the validity and reliability of assessing aphasia using standardized language assessments via an Internet-based videoconferencing system using a bandwidth of 128 kbits/sec. Thirty-two participants with aphasia due to stroke or traumatic brain injury were assessed simultaneously in either a face-to-face or online-led environment by two SLPs. Short forms of the Boston Diagnostic Aphasia Examination (BDAE-3) and the Boston Naming Test (BNT, 2nd edition) were administered. An eight-item participant satisfaction questionnaire was completed by 15 participants assigned to the online-led assessment. Results failed to identify any significant differences between the 24 subtest scores of the BDAE-3 and the BNT scores obtained in the online and face-to-face test environments (p > 0.01). Weighted kappa statistics indicated moderate to very good agreement (0.59–1.00) between the two assessors for the 24 subtests and eight rating scales of the BDAE-3, the BNT, and for aphasia diagnosis. Good to very good inter- and intra-rater reliability for the online assessment was found across the majority of assessment tasks. Participants reported high overall satisfaction, comfort level, and audio and visual quality in the online environment. This study supports the validity and reliability of delivering standardized assessments of aphasia online and provides a basis for ongoing development of telerehabilitation as an alternate mode of service delivery to persons with aphasia.