Over a third of the 3,000 women interviewed by the internet firm said it was the best way of interacting with their favourite brands, with 54% saying it was their main way of interacting with the world.
The research comes as the brand launches its Yahoo! Lifestyle site, its first attempt at specifically targeting women with female-focused content.
Yahoo’s research also shows web is on the increase as women’s main source of communication and shopping with 65% of women using a social network and 61% shopping online.
Hazel Checkley, head of Yahoo! Lifestyle, said: “Young women today are switched on and connected and going online to maintain their social lives, shop online and for advice on the many topics that are relevant to the various roles they play through out their day, be that a mother, wife, daughter or boss.”
The success of sites like Mumsnet has also meant an increase in mother’s web usage, with 63% admitting to going online to get affordable food information, according to the study.
Of working women, 42% said they had used the web to search for jobs or career advice.
Yahoo! Lifestyle sees the brand partner with the likes of Grazia, The Telegraph and Match.com to provide targeted content.
It follows the launch of AOL’s female-focused site MyDaily UK earlier this week.