No, "Helsinki" does not have a direct English translation. It is a proper noun — the Finnish name of Finland's capital.
Founded 1550 by King Gustav Vasa of Sweden as Helsingfors. Became capital of Grand Duchy of Finland (1812) under Russia. Retained both names; Finnish form official since 1917 independence.
If translated literally: "Helsinge Rapids" or "Neck Rapids". But the name itself is untranslated — like Paris, Tokyo, or Moscow.