Loris lydekkerianus is known to be the most widespread among two currently recognized species of slender loris in Sri Lanka. Here I review the distribution of L. lydekkerianus in the island, based on recent literature and data collected over fifty years ago by W. C. Osman Hill and William W. A. Phillips. According to the early literature, L. I. nordicus was distributed in the lowland dry zone of north and east Sri Lanka, while L. I. grandis was found in hills in the Central Province. Information gathered in this review along with an observation by the author, extends the distribution of L. lydekkerianus nordicus towards the southeastern coastal belt of Sri Lanka, and suggests that the actual range of the species could be larger than previously known. Recent observations raise a number of questions on the range, abundance, variation and the biogeography of the hitherto known and possibly unknown forms of slender loris, stressing the need for further studies on these little known taxa.