The 43-year-old Clarke was made an Officer of the Order of the British Empire after ending his long wait for a major victory by winning the British Open at Royal St. George's.
"It is a great honour and a fantastic way to end a great year. I am very proud for me and my family," Clarke said. "It was a life-changing moment really and in many ways my feet have not touched the floor since. And now this."
Clarke lifted the claret jug weeks after the 22-year-old McIlroy's eight-shot victory in the U.S. Open at Congressional. The second-youngest major winner since 1934, McIlroy was made a Member of the Order of the British Empire.
"It is quite humbling to be included in such a list of worthy recipients," McIlroy said. "Many people on the honours list have made huge personal sacrifices and contributed significantly to society during their lives. I feel very fortunate to be in their company."
With less than seven months to go before the start of the 2012 Olympics in London, two men involved in the organization of the Games received knighthoods.
Charles Allen, a board member on the London Organizing Committee, and John Armitt, the chairman of the Olympic Delivery Authority who is recognized for services to engineering and construction, both become sirs.
World taekwondo champion Sarah Stevenson, who will be one of Britain's leading medal prospects in London, received an MBE at the end of a year in which both her parents died.
Former Formula One world champion Nigel Mansell was made a Commander of the Order of the British Empire for services to children and young people.
The 58-year-old Mansell is the president of UK Youth, a charity that provides tools to help build young people's self-esteem, aptitude and skills.