Vietcombank sold the dollar at VND25,536, up 0.05% from Tuesday.
The greenback slid 0.23% to VND25,840 on the black market.
The State Bank of Vietnam hiked its reference rate by 0.05% to VND24,320.
Since the start of the year, the dollar has risen against the dong by 4.57%.
Globally, the dollar edged higher on Tuesday in thin holiday trading as the expected slower path of interest rate cuts from the U.S. Federal Reserve compared with other global central banks continued to command market direction, Reuters reported.
The greenback has jumped more than 7% since the end of September, powered in part by growing expectations the U.S. economy will see accelerated growth under policies from President-elect Donald Trump, while sticky inflation has dampened expectations on how aggressive the Fed will be in reducing interest rates.
The dollar index, which measures the greenback against a basket of currencies, rose 0.14% to 108.24, with the euro down 0.15% at $1.0389. The index is on track for its fifth gain in the past six sessions. Sterling weakened 0.06% to $1.2527.
Against the yen, the dollar strengthened 0.1% to 157.34 as the Japanese currency remains near levels that have recently prompted Japanese authorities to intervene in an effort to support it.
