MSEA

MSEA may refer to:
 * Mainland Southeast Asia, or Indochina
 * Mainland Southeast Asia linguistic area
 * Magadh Stock Exchange Association
 * Maine State Employees Association, the public sector union in Maine
 * MapleStory Southeast Asia
 * Metabolite Set Enrichment Analysis, a bioinformatics tool
 * Minnesota School Employees Association, an independent public sector union of classified (non-certified) public school staff in Minnesota.