Smithwick joined the show as series editor in Spring 2011, before later taking on the role of producer. She will leave the soap on Friday 5th October.
A spokesperson for Lime Pictures told Digital Spy: “After 18 months on Hollyoaks, series producer Emma Smithwick will be stepping down. Executive producers Bryan Kirkwood and Tony Wood will continue to oversee the show.
“We thank Emma for all her hard work on Hollyoaks and wish her every continued success for the future.”
During her time with the soap, Smithwick oversaw high-profile storylines including a murder, homeless issues and a high profile feud between two main characters.
Smithwick said: “It has been an extraordinary 18 months on Hollyoaks, and I have been very fortunate to work with some of the most dedicated teams in the business – from cast and crew to the writers and brilliant editorial team.
“I have also had the pleasure of working with the hugely talented and capable Bryan Kirkwood, so I know that I will be leaving the show in great hands. I am so excited for the future of the show and want to thank everybody at Lime for making my time on Hollyoaks very special.”