Development agencies and international donors’ efforts are increasingly focusing on better integrating poor and remote farmers into agricultural markets to address the chronic issues of rural poverty and hunger in low‐ and middle‐income countries. Using systematic methods for information retrieval, critical appraisal and evidence synthesis, this research aims to examine evidence on the effects of five focal types of agricultural market access interventions: (i) farm‐to‐market transport infrastructure interventions; (ii) output market information interventions; (iii) initiatives creating new marketplaces and alternative marketing opportunities; (iv) contract farming initiatives; (v) interventions improving storage infrastructure. In this review, we will study evidence of the magnitude and direction of intervention effects on agricultural, socio‐economic, and food and nutrition security outcomes. We will examine evidence of the distribution of reported effects across different contexts, interventions and sub‐groups of the population (e.g., according to sex, socio‐economic status, farm size, etc.). We will also report on included studies’ risk of bias and on what evidence is available on intervention costs, or their cost‐effectiveness. This protocol outlines this review's planned methods and the criteria for selecting and including studies in its analysis.