The actress, who plays Zara Carmichael, has been on maternity leave in recent months and gave birth to a baby boy named Bertie in May.
Walsh has already filmed a brief return visit which will see Zara back on screen in time for Christmas, but her return to set next week will see her back as a regular cast member again.
Writing on Twitter today (October 23), Walsh told fans: "Hello Loyal Twitterers, I thought you might like to know my babymoon is over & I am off back to Letherbridge NEXT WEEK. Not on screen tho (sic)."
She added: "Thank you to everyone who has asked after me & my beautiful Bertie. Zara's not back on screen 'til 2013 (apart from one surprise visit...)."
Viewers saw Zara leave Letherbridge in August as her relationship with Daniel Granger broke down. However, Matthew Chambers - who plays Daniel - recently told Digital Spy that he thinks there is hope for the pair's future.
Chambers said: "I do believe that they can be happy together again. As well as being quite volatile creatures, they do have quite a bit in common. I think it's going to be a question of whether they're able to go to another level in their relationship and also their personal lives. But I believe there is hope for them, for sure."
Doctors airs weekdays at 1.45pm on BBC One.