Vietcombank sold the dollar at VND24,440, up 0.16% from Thursday.
The State Bank of Vietnam raised its reference rate by 0.08% to VND23,904.
The greenback fell 0.20% to VND24,770 on the black market.
It has increased against the dong by 2.99% since the beginning of the year.
Globally the dollar looked set on Friday to end 2023 with a loss, reversing two straight years of gains, dragged by market expectations that the U.S. Federal Reserve could begin easing rates as early as next March, Reuters reported.
The greenback stayed broadly on the back foot on the last trading day of the year, with currency moves subdued amid a holiday lull leading up to the New Year.
Against a basket of currencies, the greenback fell 0.02% to 101.18 , languishing near a five-month trough of 100.61 hit in the previous session.