If you applied for a temporary residence permit or EU Blue Card through Latvian embassy or consulate in your country of residence and you have received a positive decision from the Office of Citizenship and Migration Affairs that a temporary residence permit or EU Blue Card has been granted to you, you will have to apply for an entry visa to Latvia unless you are from one of the 60+ countries whose citizens can enter Latvia visa-free.
Applicants who have been granted long-term D visa for work are not required to apply for additional entry visa regardless of their citizenship.