Her publicist Max Clifford said Goody, who he described as "very pale and fragile", was in a wheelchair and assisted by nurses during the service with her sons Bobby, five, and Freddy, four, at the Royal Marsden Hospital in west London.
He said it was the last thing that Goody would do publicly, adding that she had a "smile and a kiss for everyone who was there".
The reality television star had wanted the ceremony to take place in a church, but has been heavily sedated since she was transferred to the Royal Marsden Hospital for a bowel operation.
Her two sons were taken to the hospital for the service on Saturday morning by their father Jeff Brazier.
Speaking shortly before the ceremony, Mr Clifford said Jade had told him she wanted her children to "know Jesus so we can keep in touch".
He added the boys were not fully aware of what was going on with their mother's health.
He said: "They know their mother is very ill and that is something the family will help them with".
Jade's husband Jack Tweed and mother, Jackiey Budden also attended the ceremony, which involved about 20 close family members and friends.
Goody has been determined to raise as much cash as possible through media deals, the proceeds of which will go to her two sons.
The 27-year-old, who first found fame after appearing on the reality TV series Big Brother, has been told she has only weeks to live after being diagnosed with cervical cancer in August last year.
Mr Clifford said Goody had been christened in her hospital gown with her drip still attached although her ill health did not stop her enjoying the service.
The service was carried out by hospital chaplain Chris Lee and Corinne Brixton, vicar of St John's church in Buckhurst Hill, Essex, near Goody's home.
Goody had sat in a chair for most of the service before being put back into a wheelchair at the end by nurses. She kissed the hands of friends and family as she was wheeled out of the ceremony.
Mr Clifford said photographs taken of the service would be published in OK! magazine at a later date.
He said: "She finds it very hard to stay awake for more than a few minutes but she stayed awake for the 20 minutes of the service.
"It was a very positive atmosphere, after each of the boys were christened everyone clapped and after Jade was christened everyone clapped again.
"It was a very simple service. There were prayers and blessings and a few short readings."
Mr Clifford said he believed the reality TV star was saying goodbye to some people for the final time following the ceremony.
He said: "It was in my mind that she was saying a final goodbye to some people. I think everybody knew just how important it was to Jade."
"Sometimes when people are very, very ill they need to focus on something and it keeps them going."
Mr Clifford said Goody was in no doubt that she wanted photographs to be taken of the event and published.
He said: "Obviously the money from this will go to her boys and that is what she's always wanted."
He added he thought it unlikely she would leave the hospital.
He said: "Speaking for myself, I'm no medical expert but I doubt she will leave. This is the best place for her; last week she was in a great deal of pain and nobody wants her to be like that again."
He said for several of the people at the ceremony it could well be the last time they saw the star.
The christening was the last publicised event of Goody's short life.
Mr Clifford said the planned television interview with Piers Morgan would probably not now take place.
He added: "I hope the boys get a chance to see her again. It's the first time they've seen her this weak.
"The two things she said to me were she wanted to get married and have the christening and she has done them both and done them her own way, with style."
