Sneijder, who is currently on the books of Turkish giants Galatasaray, played a key role in Inter Milan's treble triumph in 2010 under the management of Jose Mourinho.
Mourinho has returned to the Blues, and Van Gaal is hopeful Sneijder reunites with the Portuguese for the sake of the player's international career.
"I know Chelsea and Jose Mourinho want Sneijder," Van Gaal told Turkish newspaper Vatan.
"In my opinion, if possible Sneijder should leave Galatasaray and join Chelsea.
"Playing under Mourinho again would improve his performances and help him regain his form for the national team."
Sneijder started six times for his country in their successful World Cup qualifying campaign, scoring once and claiming two assists.
Netherlands finished top of Group D with nine wins and a draw.