This is the first comprehensive introduction to the flies of the subfamily Tachydromiinae (Hybotidae) of Singapore. The monograph summarizes all publications on the Tachydromiinae of Singapore and includes new data resulting from mass-trapping surveys made in Singapore during the last six years. A few samples from Malaysia (Johor province, Pulau Tioman and Langkawi) have been also included in this study. In Singapore the Tachydromiinae are the most diverse group of Empidoidea (except Dolichopodidae) and currently comprise 85 species belonging to the following nine genera: Platypalpus (1), Tachydromia (1), Chersodromia (6), Pontodromia (1), Drapetis (5), Elaphropeza (60), Crossopalpus (1), Nanodromia (3) and Stilpon (7). All species are diagnosed and illustrated. The following 28 species are described as new for science: Chersodromia bulohensis sp. nov. (Singapore), C. glandula sp. nov. (Singapore, Malaysia), C. malaysiana sp. nov. (Singapore, Malaysia), C. pasir sp. nov. (Malaysia), C. sylvicola sp. nov. (Singapore), C. tiomanensis sp. nov. (Malaysia), Crossopalpus temasek sp. nov. (Singapore), Drapetis bakau sp. nov. (Singapore, Malaysia), D. hutan sp. nov. (Singapore), D. laut sp. nov. (Singapore, Malaysia), D. mandai sp. nov. (Singapore), D. pantai sp. nov. (Singapore, Malaysia), Elaphropeza chanae sp. nov. (Singapore), E. collini sp. nov. (Singapore), E. gohae sp. nov. (Singapore), E. kranjiensis sp. nov. (Singapore), E. lowi sp. nov. (Singapore), E. semakau sp. nov. (Singapore), E. shufenae sp. nov. (Singapore), Nanodromia hutan sp. nov. (Singapore), N. spinulosa sp. nov. (Singapore), Platypalpus singaporensis sp. nov. (Singapore), Pontodromia pantai sp. nov. (Singapore), Stilpon arcuatum sp. nov. (Singapore), S. neesoonensis sp. nov. (Singapore), S. nigripennis sp. nov. (Singapore), S. singaporensis sp. nov. (Singapore), S. weilingae sp. nov. (Singapore). A redescription is given for Crossopalpus exul (Osten-Sacken, 1882) (Taiwan). Males of Elaphropeza feminata Shamshev & Grootaert, 2007 and E. modesta Shamshev & Grootaert, 2007 as well as females of Elaphropeza ubinensis Shamshev & Grootaert, 2007 and Nanodromia narmkroi Grootaert & Shamshev, 2003 are described for the first time. Keys to genera and species, which are generally applicable to the whole of Southeast Asia, are compiled. An analysis of the species ecological preferenda is presented.</p