Wearable devices like smartwatches sit at the intersection of two product categories: consumer technology and fashion. The way companies brand wearable devices they produce comes in several variations, with technology companies having their own smartwatches, fashion companies having their own smartwatches, and fashion and technology companies having brand alliances through their smartwatches. The purpose of this study is to understand the effects that these various branding models have on consumer perceptions of wearable devices. The sample consisted of 200 adults recruited from Prolific. An online survey exposed participants to variations of fictional smartwatches under different branding structures and had them rate the devices across several dimensions. The results indicate that fashion brands can increase the perceived functionality and modernity of a wearable device if they co-brand it with a technology brand. They also indicate that technology brands can create wearable devices with higher perceived luxury, exclusivity, design, and physical quality by co-branding with a luxury fashion brand. Additionally, in co-branded smartwatches, the perceived qualities of a brand can cause perceptions of the partner brand to change as well. This study is important to understanding how branding strategies of wearable devices can impact the way that consumers perceive the devices. It also provides insight into the spillover effects of co-branding on each brand involved.