It also announced a funding package of $3.9 million to assist unions hit by the postponement.
The ninth edition of the tournament was scheduled to be hosted in Auckland and Whangarei from 18 September to 16 October but World Rugby said last week it would be difficult to host the event as planned.
More than 600 players, staff and tournament personnel were expected to travel for the event, leading to risk surrounding safe and reliable travel among other problems.
"The executive committee also endorsed work to develop and fund a Rugby World Cup 2021 high performance preparation and competition programme for qualified teams and teams still competing in the qualification process," World Rugby said.
"The programme will be underpinned by a 2 million pounds funding package and will focus on providing teams with international competition to give them the greatest opportunity to be at their best in New Zealand next year."
The tournament will be the first women's Rugby World Cup to be held in the southern hemisphere, and is due to feature New Zealand, England, Canada, France, Australia, United States, Wales, South Africa, Fiji and three qualifiers.
New Zealand are the current holders, having defeated England 41-32 in the final in Belfast in 2017.
"The top players in the women's game should be guaranteed the stage that they deserve, with the opportunity for their family and friends to be able to attend, and also the wider national and international rugby family," World Rugby Chairman Bill Beaumont said.
"Postponement by a year should enable us to enjoy the benefits of the global vaccination programme, easing the burden on international travel requirements and within New Zealand itself."
Dates for the postponed tournament will be announced shortly.