A silicone microemulsion composition obtained by microemulsifying a carboxy-modified organopolysiloxane, and having a lower surface tension than conventional microemulsions. The composition includes 100 parts by mass of a specific carboxy-modified organopolysiloxane (A), 25 to 75 parts by mass of a specific polyether-modified organopolysiloxane (B), 0.1 to 10 parts by mass of an anionic surfactant, and 20 to 6,000 parts by mass of water, wherein the average particle size of the emulsion particles is not more than 100 nm.