The triathlon governing body added that at least 48 months must have elapsed since the transgender athlete has competed as a male in any sporting competition.
The policy, formed after consulting athletes, medical and legal experts among others, will be put in place in September.
"We have been studying this matter for over a year, we have listened to the voices of all World Triathlon stakeholders," World Triathlon President Marisol Casado said.
"We are a small international federation, but one that has always had inclusion and gender balance in our DNA. The policy that we have just approved shows that we are prioritising the fairness principle but showing inclusiveness.
"It is fully aligned with the IOC's recommendation, and similar to what other international federations have done in the last months."
The International Olympic Committee said in November that no athlete should be excluded from competition on the grounds of a perceived unfair advantage due to their gender as it released a new framework on transgender inclusion.
But it added it was not in a position to issue regulations that define eligibility criteria for every sport, leaving it up to federations to determine if an athlete was at a disproportionate advantage.
World Athletics and FIFA are among federations that are also reviewing guidelines on the involvement of transgender athletes following world swimming body FINA's ruling to ban anyone who has been through male puberty from elite women's competitions.
Last month, British Triathlon banned transgender athletes from competing under the female category at the elite as well as grassroots levels, instead allowing them to participate in an "open" category alongside men.
"World Triathlon will monitor the situation and be open to reviewing its policy", Casado added.
