Vietcombank sold the dollar at VND25,502, a 0.09% increase from Tuesday. The greenback fell 0.27% to VND25,650 on the black market.
The State Bank of Vietnam lowered its reference rate by 0.09% to VND24,288.
Since the beginning of the year, the dollar has increased by 4.43% against the dong.
Globally, the U.S. dollar held near a 6-1/2-month peak against major peers on Wednesday as markets sized up so-called Trump trades ahead of key U.S. inflation data later in the day, Reuters reported.
The U.S. dollar index, which measures the currency against a basket of currencies, tacked on 0.02% to 106.01, not far from Tuesday's high of 106.17, its strongest since May 1.
The euro languished near a one-year low of $1.0596 hit on Tuesday, and was last down 0.05% at $1.061875.
Sterling was flat at $1.2746, under pressure from a broadly firmer greenback.
The dollar edged up about 0.17% against the yen to 154.88 after touching 154.934, its highest against the Japanese currency since July 30.
The dollar is reaping the benefits of Republican Donald Trump's victory in the U.S. presidential election last week, with investors pricing in policies of lower taxes and trade tariffs under the incoming administration that are seen as inflationary.