The 60-year-old deceased was among the two injured who were rushed to the hospital.
According to the Anadolu news agency, the blast occurred at 11:07 am (local time) at the Varby Gard metro station, situated in the southern part of the city.
The police force refuted claims that the man was unlikely to have been purposely targeted by whoever left the explosive at the metro station.
The Aftonbladet newspaper reported that the blast was from was a hand grenade, though this is yet to be confirmed by the police.
The metro station has been shut and nearby areas have been cordoned off from the public as an investigation is currently on.
It is yet to be ascertained whether it is a terrorist incident or not.
Stockholm is on high alert since the April 2017 attack in the heart of the city, when a truck was deliberately driven through the crowd, killing five people and injuring 14 in the process.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)