Washington is a firm friend of the Saudi kingdom, but has often been embarrassed by its ally's conservative religious and social attitudes.
"President Donald J. Trump commends the Kingdom of Saudi Arabia's decision today to affirm the right of women to drive in the kingdom," a White House statement read.
"This is a positive step toward promoting the rights and opportunities of women in Saudi Arabia."
Earlier, State Department spokeswoman Heather Nauert hailed the "very positive sign."
"We're just happy today," she added.
Earlier, Saudi officials had announced that it would allow women to drive from next June, a victory for a long campaign by women's rights activists.
"We will continue to support Saudi Arabia in its efforts to strengthen Saudi society and the economy through reforms like this," the White House said.