<p>The forests of the Solomon Islands are some of the most important in the world, given their high biodiversity and function as carbon sinks at this time when climate action is becoming a number one global priority. In addition, these forests have been, for millennia (and continue to be), a vital economic, cultural and spiritual resource for the Indigenous peoples of the Solomon Islands. Nevertheless, scientific evidence clearly indicates that current forest harvesting in the Solomon Islands is unsustainable, with annual harvesting at about 10 times the sustainable yield. If unchallenged, such harvesting will lead to forest and landscape degradation and socio-economic problems with potentially catastrophic impacts for the local communities. However, achieving sustainable forestry is not merely a scientific problem – it is a problem of governance. The central research question of this study is: Do the Statutory Law and Customary Law co-governance arrangements embedded in the Solomon Islands <i>Constitution</i>, legislation and policies facilitate or hinder sustainable forestry in the Solomon Islands? This research question was answered in two steps of data collection: The first step was the examination of official and other institutional documents, historical references, laws and regulations, reports and scholarly articles. This examination provided the background for understanding the history of forest management and the characteristics of the Solomon Islands' forests governance system relating to the sustainability of its forest resources. The second stage of data collection involved in-depth semi-structured interviews with 16 interviewees from Honiara (the national capital of the Solomon Islands), 6 from Taro (Provincial Headquarters of Choiseul Province) and 13 from Loloko village (a village in Choiseul Province). These interviewees were all Indigenous Solomon Islanders, comprising 29 males and 6 females. The aim of this second stage of the data collection was to ascertain what is actually happening on the ground with the laws and institutions involved in the governance and management of forests in the Solomon Islands. The study proceeded to identify how forest-relevant laws, policies and institutions relate to the pre-existing traditional customs and institutions of the Indigenous people's governance and management of themselves and with their customarily owned forest resources. This information was then used for determining the interrelationship between the state system and the traditional system, whether there is a need for improvements and how that can be addressed.</p> <p>The study finds that the Solomon Islands' forests governance system is predominantly hierarchical in nature, making it ineffective for managing sustainable forestry. The ineffectiveness is mainly caused because of the Solomon Islands pluralistic legal system, land ownership that is predominantly Customary, and its ceaseless ongoing issue of limited resources and capacity. To improve the forest governance system, this research identifies five key principles (with related elements) of forest co-governance that are relevant to the context of the Solomon Islands: uphold Statutory and Customary Law, partnership between the state and landowners, access to justice and resolution of conflicts, enforcement and accountability, and access to and provision of information. </p>