Alex Kay-Jelski, Director of BBC Sport, said: "The response to the Women's Rugby World Cup so far has been phenomenal. These figures reflect not only the growing appetite for the women's game, but also the impact of our commitment to telling these stories in fresh, creative and digitally accessible ways."
Matches have also been covered in live pages on the BBC Sport website. The most popular was England v USA, which had 757,000 views.
Games have also been streamed on the iPlayer and Sport apps, attracting a combined 5.8m streams so far. Non-home nation matches have also been popular, with 200,000 watching France v South Africa in Group D.
All four quarter-finals, including England's clash with Scotland, will be broadcast on BBC Two and iPlayer across this weekend on 13 and 14 September.
The semi-finals will also be live on TV, with the final on Saturday 27 September live on BBC One.