Vietcombank sold the dollar at VND25,512, marking a 0.03% increase from Thursday and the highest-ever rate.
The greenback fell 0.04% to VND25,709 on the black market.
The State Bank of Vietnam hiked its reference rate by 0.03% to VND24,298.
Since the beginning of the year, the dollar has increased by 4.47% against the dong.
Globally, the dollar was headed for its best week in more than a month on Friday, buoyed by expectations of fewer Federal Reserve rate cuts and the view that Donald Trump's policies could further stoke inflation when he assumes office in January, Reuters reported.
The greenback hovered near a one-year high against a basket of currencies at 106.81 and was eyeing a weekly gain of 1.76%, which would mark its best performance since September.
Sterling was in turn on track for its steepest weekly fall since January 2023 at roughly 2%. It last ticked up 0.06% to $1.2676.
The euro last bought $1.0541, languishing near a one-year low hit in the previous session. It was headed for a weekly fall of 1.67%, also its worst in over a month.
The yen was last 0.1% lower at 156.39 per dollar, on track for a weekly decline of 2.4%.
The Japanese currency has fallen nearly 11% since its September peak and weakened past the 156 per dollar level for the first time since July in the previous session.
Higher trade tariffs and tighter immigration under President-elect Trump's incoming administration are projected to fuel inflation, potentially slowing the Fed's easing cycle longer term.
Expectations for deeper deficit spending are also lifting U.S. Treasury yields, providing the dollar with additional support.