Rule is the second overseas player to agree to move to Sandy Park this month after Italy winger Francesca Granzotto.
“Rugby has given me so many opportunities and has made me the person I am today,” Rule said.
“Getting the chance to join Exeter is a part of that journey to grow my rugby but also make new connections and see what the hype is about this England comp[etition] that I keep hearing about.
“The plan is to make Black Ferns’ Rugby World Cup squad then carry on to join Exeter later in the year.
“All I can say at this point is all my focus is on the World Cup but once that’s done, I’m really excited to rip into the season with Exeter Chiefs and hopefully play lots of rugby and take my game to another level.”
Exeter finished fifth in the PWR last season, narrowly missing out on a place in the play-offs.
The Women’s World Cup takes place in England between 22 August and 27 September.