The actor, who played vengeful Simon Walker on the Channel 4 soap, will feature in an upcoming storyline with Doctors regular Kevin Tyler (Simon Rivers).
Newbon's character Michael Faulks is treated by Kevin after being involved in a freak accident.
As the story plays out, Kevin discovers that Michael is emotionally cut off from his wife Emily and is only able to bond with his pet Labrador Jet.
A show insider told Digital Spy: "Kevin forces Michael to realise he needs to change if he doesn't want to lose Emily, but is it too little too late?"
The role of Emily will be played by Jennifer Biddall, who was also a Hollyoaks cast member between 2005 and 2008.
Newbon appeared on Hollyoaks for almost a year from May 2012 and featured in a dark storyline as Brendan Brady's nemesis. The plot reached its conclusion in March last year when Walker was killed by an oncoming train in his final showdown with Brendan (Emmett Scanlan).
Doctors is enjoying a strong start to 2014 as several recent episodes have hit the 1.7 million mark in the show's lunchtime slot on BBC One, peaking at 1.8m for last Thursday's episode.
Newbon and Biddall's guest appearances air on Monday, April 28 at 1.45pm on BBC One.
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