The Prince of Wales presented Miss Ennis with the honour during an investiture ceremony at Buckingham Palace.
The 25-year-old, who won gold in the heptathlon event at last year’s European Championships, said she briefly discussed with Charles how training was going while he presented the award.
“He asked me how training was going and told me he was looking forward to the Olympics,” Miss Ennis said.
“He said he hoped this was a boost for me. It is a boost, not only for me, but also for athletics to help lift the sport’s profile.”
When asked if the award felt as good as receiving a gold medal, she said: “It’s definitely up there.”
Miss Ennis said 2008 had been a disappointing year but it also set the stage for a significant comeback.
The Sheffield-born athlete was forced to pull out of the Beijing Olympics because of a foot injury but she then bounced back to win the world title in Berlin the following year.
“I went from one extreme to the other,” she said.
“It was a massive blow to be injured and then going on to be the best in the world has been a major highlight in my career.”
She also won silver in Daegu earlier this year and has been heavily involved in marketing next summer’s London Olympics.
Tim Brooke-Taylor became the third and final star of 1970s TV comedy series The Goodies to receive an OBE for decades in the entertainment industry.
He said it was ironic that he and fellow actors Graeme Garden and Bill Oddie used to poke fun at the Government’s readiness to hand out OBEs in the ‘70s.
“That was in the days when we had a Prime Minister that used to give them away to all his friends,” he said.
“But I have to admit one has to bite one’s tongue.”
“We can now all three sit on our bike together with our OBEs,” he added, referring to the three-seater bicycle they rode in the show.
Conceptual video artist Gillian Wearing said she never thought she would be at the Palace receiving an OBE for her work.
“It’s a complete surprise,” she said.
“It’s rare for an artist to be recognised. There isn’t many awards in our field, not like actors, so it’s a real honour to be honoured this way.”
The 1997 Turner Prize winner combines art and film to highlight the conflict between established behaviour and what people do on impulse.
Her work includes Confess All On Video, where people dressed in masks and wigs for anonymity talk about their secrets, and Self Made, a film where people use method acting to explore their fantasy selves.
One of London’s top figures in public relations, Gary Farrow, received a call last night from one of his biggest clients, Sir Elton John, before his big day today.
Hobbling on crutches, Mr Farrow was presented an OBE for his work in the music industry and charity endeavours.
Mr Farrow said he should be in bed recovering from a knee operation, but was not prepared to miss the occasion.
“Elton is in Singapore on tour and he rang me last night to wish me good luck and offer congratulations,” Mr Farrow said.
He said Charles raised concerns about file sharing on the internet with him during the presentation.
“He was concerned about the demise of the record industry and how we can get it back,” he said.
Mr Farrow was involved with Music Therapy Charity for about 20 years.
The charity helps children with mental and physical disabilities and emotional problems communicate through music.
Sainsbury’s chief executive Justin King received a CBE for his contribution to the retail industry.
Mr King said the highlight of his career was leading the turnaround of Sainsbury’s.
“I think ... it’s the things we do beyond our retail business that makes the difference. Whether we’re involved in children’s sport or fair trade, that marks the business out,” he said.
The founder and chief executive of Stagecoach Group, Brian Souter, was also awarded a knighthood.
Sir Brian said he started his career in the transport industry as a bus conductor.
“I had no idea my journey would take me all the way to the palace one day,” he said.