The SEASTAR Steering Board (SB) is organized to deal with issues related to the SEASTAR collaboration. The SB is composed of members of the collaboration elected by the collaboration and the two spokespersons. The first SB is composed of 6 elected members. The SB is chaired by the two spokespersons. Chief scientists connected to SEASTAR are ex officio members of the SB.
| Spokesperson | DOORNENBAL, Pieter | RNC, RIKEN | ||
| Spokesperson | OBERTELLI, Alexandre | CEA, Saclay | ||
| Elected member | AOI, Nori | RCNP, Osaka University | ||
| Elected member | CORSI, Anna Maria | CEA, Saclay | ||
| Elected member | LEE, Jenny | Hong Kong Univ. | ||
| Elected member | MOTOBAYASHI, Tohru | RNC, RIKEN | ||
| Elected member | NIIKURA, Megumi | University of Tokyo | ||
| Elected member | NISHIMURA, Shunji | RNC, RIKEN | ||
| Ex-officio | SAKURAI, Hiroyoshi | RNC, RIKEN | ||
| Ex-officio | UESAKA, Tomohiro | RNC, RIKEN |