The arms and a quantity of ammunition were found at a house in Church Road, East Wall, at about 13:40 GMT.
A man in his 50s was arrested at the scene. He is being questioned at Mountjoy garda station in the city.
A police spokesman said the search was part of ongoing investigations into the activities of dissident republicans in the Dublin area.
Police have seized four handguns and a shotgun in a raid linked to dissident republicans in Dublin on Saturday.