Masaki Ejima (?? ??, Ejima Masaki, born 6 March 1999) is a Japanese athlete specialising in the pole vault.
He represented his country at the 2019 World Championships in Doha without qualifying for the final.
In 2018 he won a bronze medal at the World U20 Championships in Tampere.
His personal bests in the event are 5.71 metres outdoors (Kisarazu 2019) and 5.50 metres indoors (Pajulahti 2017).