The Arabian Peninsula remains a relatively poorly surveyed region for avian biogeography, where artificial wetlands may provide important stopover and refuge sites for water birds. We report a record of Medium Egret Ardea intermedia at Ash-Shahmah Dam within the King Abdulaziz Royal Reserve, Saudi Arabia, on 1 November 2019. This represents the second locality in Saudi Arabia where the species has been documented, following its previous record from Jizan, and provides additional evidence of its occurrence in the country, extending its known distribution to the arid interior north of Riyadh. Recent taxonomic studies have supported the recognition of three distinct species within the former “Intermediate Egret” complex: Ardea intermedia, A. brachyrhyncha, and A. plumifera. Although A. intermedia is primarily distributed in South and Southeast Asia, its confirmed occurrence in Saudi Arabia highlights the importance of careful identification of Intermediate-type Egrets in the Arabian Peninsula. Identification outside full breeding plumage remains challenging because of overlap in external characters; therefore, species identification should consider a combination of bill and lores coloration, tibial and tarsal coloration, bill shape, gape position, and overall structural characters. The Ash-Shahmah record, documented within a protected area established in 2018, also highlights the value of protected areas and systematic ornithological monitoring in improving knowledge of the Saudi avifauna and detecting species that may have previously been overlooked.