It comprised $8.8 billion in investment pledges, up 40%, and $9.35 billion in additional investment in existing projects and acquisitions.
The investments went into 18 sectors led by manufacturing, which attracted nearly $13 billion, up 15%.
The property sector was second at $1.7 billion, down 47%.
Though down 15%, Singapore was the leading investor with $3.83 billion, followed by China, Japan and South Korea.
Hanoi attracted the most FDI, $2.34 billion, a nearly three-fold rise.