Soseono (66/7 – 6 BCE) or Yeon Soseono (Korean: 연소서노; Hanja: 延召西奴) was the second wife of King Dongmyeong and a key figure in the establishment of both Goguryeo and Baekje. She was the mother of Biryu and Onjo, whom they were her sons from her first marriage with Wutae.