Vietcombank sold the dollar at VND24,530, up 0.25% from Tuesday.
The State Bank of Vietnam raised its reference rate by 0.06% to VND23,885.
The greenback went up 0.08% to VND24,820 on the black market.
It has increased against the dong by 3.37% since the beginning of the year.
Globally the dollar remained under pressure on Wednesday, while the euro flirted with a four month peak, as expectations that the Federal Reserve would soon cut interest rates take hold in the market, with thin year-end flows keeping movements limited, Reuters reported.
With traders out for holidays globally until the New Year, the curtailed week is likely to see muted volumes.
The dollar index, which measures the U.S. currency against six rivals, was at 101.54, just shy of the five month low of 101.42 it touched last week. The index is on course for a 1.9% drop in 2023 after two straight years of strong gains on the back of the Fed hiking rates to battle inflation.