This research presented within this PhD thesis sets out to develop new models of social media use for local government affiliated museums that care for archaeological archives (LAMA). The research was conducted in response to an emerging need for these institutions to engage more effectively with stakeholder communities in light of pressures on funding, the diversification of the heritage agenda, and in response to the increasingly community orientated nature of the museum in contemporary Britain. The thesis sets out to characterise and critically review current social media use by local museums and to propose new models of use that are informed by institutional objectives and co-designed with museum stakeholder communities. The findings of the research and the resulting recommendations are based upon an extensive review of sectorial practice, interviews with practitioners from international museums recognised for their exemplary use of social media, and a substantial period of participative action research conducted at a LAMA partner institution; Hampshire Cultural Trust. The thesis proposes that more effective use of social media can aid LAMAs in re-aligning institutional practice so as to incorporate community involvement in interpretation and decision making. The research suggests that new models for social media use have the capacity to recast the role of the local museum in contemporary society as a collaborative, discursive and pluralistic social institution with an integral social function. The primary output of the PhD is a framework which LAMA institutions (as well as other museums with locally derived collections) can use to plan and implement transformative social media practice.