This systematic review paper attempts to present the current database on the effects of explicit connected speech instruction on English as a Second Language (ESL) or English as a Foreign Language (EFL) learners’ perceptive skills and connected speech production. A total of 22 studies were gathered across the digital database through selective searching of key terms. Using the format of the review by Thomson and Derwing (2014), the following information was tabulated: participants’ demographics, theoretical paradigm, scope of training, training input, duration of instruction, nature of assessments, and whether or not there was a significant improvement in learners’ perceptive skills and connected speech production. The findings have generally shown a consensus among the studies that explicit instruction of connected speech was effective and had positively contributed to the improvement of learners’ perceptive skills and connected speech production. This paper adds to the corpora of literature on connected speech in ESL and EFL contexts and raises awareness of the significance of connected speech instruction in ESL or EFL learning contexts.