The pair have landed the roles of village newcomers Ali Spencer and Ruby Haswell, who are due to make their first appearance on screen in the autumn.
Ali is the sister of troublesome Rachel Breckle (Gemma Oaten), who made her debut last week when she arrived at the Dingles' home for a furious showdown with Sam.
Just as fiery as her outspoken sibling, Ali breaks up with her husband and leaves her flat on the Hotten estate, hoping for a new start in the village with her two children Sean and Amelia, played by 14-year-old Luke Roskell and 7-year-old Daisy Campbell.
However, Ali's life is far from uncomplicated as she has left her husband for Ruby, much to the horror of her tearaway son.
A statement released by the show teased: "Ali is determined to make her new life in Emmerdale with Ruby work, regardless of Sean's reaction and the pleas of her determined ex-husband to give their marriage another go. When faced with the reality of Ali's baggage, does Ruby really feel the same?"
Hollis portrayed the role of Yvonna Karib on Shameless between 2003 and 2009. She also played Tina Crabtree in the 2004 feature film Mischief Night.
Speaking of her casting, she commented: "As a Leeds girl myself, getting a role as a new regular character for Emmerdale in my home town is a dream come true. I'm really excited to be playing Ali."
Eyo, meanwhile, played Denny Blood in Bad Girls from 1999 to 2003 and has also had recent roles in Silent Witness and Waterloo Road.
Of her new part as Ruby, she said: "I'm over the moon and can't wait to get started. Being part of a show that I've grown up watching is amazing and Ruby is going to be a lot of fun to play."
Ali and Ruby will arrive on screen in October and have been tipped to cause a stir with their no-nonsense attitudes.
Emmerdale's series producer Stuart Blackburn said: "Ali and Ruby are down to earth, gritty, funny and likeable and after leaving her husband of 15 years, Ali has a lot riding on making her new life in Emmerdale work."
> Read our recent interview with Emmerdale's series producer Stuart Blackburn
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