The charity campaigner, 30, is expecting her child with her boyfriend, who she has been with for two years and moved in with last year.
Katie revealed her news today (22 September), adding that they have been trying for a baby for some time.
Speaking to the Sunday Mirror, who she writes a column for, Katie said: "I just want to shout it from the rooftops!"
She has since thanked her fans for their best wishes on Twitter, adding that she is unfortunately suffering from morning sickness.
"Overwhelmed by all the congratulations tweets and best wishes!" Katie tweeted. "Thank you so much, has completely taken my mind of today's morning sickness! X"
In 2008, Katie suffered horrific burns in a chemical attack set up by her ex-partner and was placed in an induced coma for 12 days.
Since then, she has undergone dozens of operations and has set up her own charity to help others - The Katie Piper Foundation.
The Foundation, which is backed by Simon Cowell, supports fellow burns victims, both children and adults, through groups and special workshops.
Katie has also appeared in several documentaries about her own experiences and those of others and, in 2009, recorded an alternative Christmas message for Channel 4 viewers.
In 2011, she won a Pride Of Britain award for her courage and determination.
See who else is expecting a baby in our gallery below!
Copyright: Vimeo / Weiss Eubanks