The forthcoming arrivals will fill some of the gaps which will be left behind when a number of cast members depart the Channel 4 teen drama in the months ahead.
Marquess joined Hollyoaks in January as a replacement for Lucy Allan, who was the programme's series producer for just over a year. He has since started work on a major revamp of the serial.
Writing on the show's official website, Marquess promised: "There are lots of exciting things coming up with a lot of dramatic, funny and heartbreaking storylines in the pipeline.
"Sadly we will be losing some characters as storylines progress and actors' contracts come to an end. But we've created lots of fantastic new characters that we're currently casting for.
"We're particularly excited about the new family that will join the show in the summer - and guarantee they'll bring glitz, glamour and great stories to the Hollyoaks village!"
Marquess confirmed that he is "really excited" to be part of Hollyoaks and considers his role to be a "huge challenge, but also a massive honour".
The soap's new recruit has previously worked on Brookside, The Bill and Family Affairs.