Changes in the organization’s culture, structure, processes, and strategy (Armenakis et al., 1993) have become essential for organizations to thrive and survive in an increasingly volatile, uncertain, and complex business environment (Hanelt et al., 2021; Kotter, 2007; Kotter et al., 2021). Previous research has helped to identify several reasons for the difficulties and failures encountered during the change journey, such as the emergence of forces of persistence (Hill & Rothaermel, 2003; Kotter & Schlesinger, 1979; Warrick, 2023). Particularly in family firms, organizational change may be foregone due to the trade-off between the need for organizational change and the continuity resulting from the family’s attachment to existing assets, values, and traditions (Diaz‐Moriana et al., 2022; Kotlar & Chrisman, 2019; Liu et al., 2023). In light of these challenges, change agents have been proposed to drive change initiatives in organizations (Battilana & Casciaro, 2012; Boonstra, 2023; Specht et al., 2018). Research on inter-organizational innovation collaborations has highlighted the benefits of collaborations for organizations, not only in terms of innovation outcomes (De Groote & Backmann, 2020; Hogenhuis et al., 2016; Soh & Subramanian, 2014), but also in terms of organizational change, especially in the context of asymmetric innovation collaborations1 (Corvello, Steiber, & Alänge, 2023; Rigtering & Behrens, 2021; Weiblen & Chesbrough, 2015). However, the latter studies do not provide insight into the specific mechanisms developed to support the change process within the established organization, nor do they detail the types of change that these mechanisms address. Hence, we lack an understanding of the interaction between the external and internal change agents (Birkinshaw et al., 2008; Mol & Birkinshaw, 2014),which is even more important in the context of organizational change in family firms, because owning families, which play a dominant role in change (De Massis et al., 2019; Issah et al., 2023; Liu et al., 2023), are often characterized by inertia (Chirico & Nordqvist, 2010) and often show resistance to external organizations such as start-ups (Bigliardi & Galati, 2018; Feranita et al., 2017; Freeman & Engel, 2007). Therefore, we pose the following research question: How do start-ups interact with family firm internal actors to drive organizational change in family firms in the context of innovation collaborations? Based on a qualitative study of six cases of family firms engaging in innovation collaborations with start-ups (including 40 semi-structured interviews), we develop a model detailing the role of start-ups in organizational change in family firms. Our study aims to make the following three contributions. First, we extend previous knowledge (Corvello, Steiber, & Alänge, 2023; Rigtering & Behrens, 2021; Weiblen & Chesbrough, 2015) by theorizing the roles of start-ups in the change process of established organizations (i.e., “seeder,” “pollinator,” “facilitator”) and by identifying the concrete mechanisms that start-ups develop during collaboration to fulfill these roles. Second, while previous research has theorized the crucial role of the owning family in organizational change (De Massis et al., 2019; Kotlar & Chrisman, 2019), we extend this knowledge by shedding light on the important interplay (Birkinshaw et al., 2008; Mol & Birkinshaw, 2014) between the owning family, other internal family firm actors, and external actors. Third, we contribute to the research on organizational change in the context of family firms (Duran et al., 2016; Naldi et al., 2007; Soluk & Kammerlander, 2021) by providing evidence on the type of change achieved through collaboration with external organizations such as start-ups, a granular view of the nature and sequence of organizational change and the underlying factors.