Seija is a given name. Notable people with the given name include:
Seija Ballhaus (born 2000), German judoka Seija Karkinen (born 1936), Finnish jurist and politician Seija Pöntinen (1934–1998), Finnish hurdler Seija Simola (1944–2017), Finnish singer Seija Toro (), Finnish diplomat
See also Seijas, surname