Sustainable conversion of uneconomic rubber monocultures is essential for restoring degraded tropical rainforests and achieving the goals of the UN Decade on Ecosystem Restoration (2021–2030). Here, we discuss existing ecological restoration approaches that may be applicable to converting rubber monocultures in protected and marginal areas with high conservation value but less economic potential. Before selecting restoration interventions, practitioners should conduct comprehensive assessments of landscape context, land-use history, forest regeneration status, and resource availability. Natural forest regeneration is typically a low-cost restoration option for rubber monocultures that have encroached into protected areas, where nearby natural forest fragments can provide seed sources. In other marginal areas, assisted natural regeneration and active planting can promote more rapid recovery. The restoration strategies outlined here can support the restoration of 1,900,000¿ha of rubber monocultures in marginal zones and other economically unsustainable monoculture plantation crops, thereby making a significant contribution to global restoration targets by 2030.