Purpose: Extensive literature exists about the effects of LSVT LOUD®, SPEAK OUT!®, and SPEAK OUT!® Therapy Group programs on voice and speech outcomes for individuals living with Parkinson Disease (PD). Prior studies have reported increased speech intelligibility and vocal intensity among participants with PD immediately upon completing one-on-one individual programs (including LSVT LOUD® and SPEAK OUT!® therapy). However, few researchers have reported longitudinal data on the specific effects of the SPEAK OUT!® Therapy Group program on participants’ cognitive, self-reported swallowing, depression, and voice-related quality of life (QoL) status. Therefore, the current study examined the effects of SPEAK OUT!® Therapy Group participation for fourteen participants with PD in multiple domains, including cognition, self-reported swallowing status, depression, and voice-related QoL across two years. Methods: Data were collected at six-month intervals over two years. Participants included a treatment (TX) group that attended weekly SPEAK OUT!® Therapy Group sessions and a control (CN) group that did not receive any speech therapy services for their PD symptoms. Results: No statistically significant group differences were found for the different measures. However, descriptive statistics showed maintenance, rather than decline, in the TX group for cognition and other domains compared to the CN group at the end of two years. In contrast, the CN group demonstrated a slight cognitive decline during the same period. Conclusions: The current study provides evidence of possible slow progression of non-voice domains such as cognition, self-reported swallowing, and depression after participating in the SPEAK OUT!® Therapy Group program. However, additional studies are warranted.