From 2010 until December 2011, the actress was involved in a groundbreaking gender identity storyline with her character, previously named Jasmine.
Her official website has confirmed that Atkin will make a one-episode stint as ex-army soldier Lainey Craig who suffers with foreign accent syndrome, a speech impediment usually the result of a brain injury.
Digital Spy exclusively revealed last September that Atkin would be bowing out of her role on Hollyoaks.
She said at the time: "Playing Jason has been a phenomenal first role out of drama school. I feel extremely blessed to have performed such a didactic and challenging role.
"I would like to thank everyone for an immensely rewarding year, Jason has been an incredible part, however I am now very excited to explore what other roles the industry has to offer."
She will make her appearance on hospital drama Holby City on Tuesday, June 26 - under a fortnight's time - at 8pm on BBC One.