Consumer advocates were concerned the delay would put investors at risk.
"Overwhelming evidence shows even before the rule has been fully implemented, it's bringing down costs for advice and investment products," said Roper of the Consumer Federation of America.
"It's reducing the incentives advisors have to act in ways that aren't in the customers' best interest," she said.
AARP, which represents older Americans and is a supporter of the fiduciary rule, expressed its disapproval of the president's move.
"Today's executive action harms middle-class Americans by pushing back the compliance date," said Nancy LeaMond, AARP's executive vice president, in a statement.
"Unfortunately for many Americans, today's executive order means they will continue to get conflicted financial advice that costs more and reduces what they are able to save in retirement," she said.