There are also accolades for veteran actresses Angela Lans-bury, Penelope Keith and Lynda Bellingham, who was diagnosed with cancer earlier this year, as well as actor Michael Crawford and DJ Pete Tong.
Apprentice star and vice-chairman of West Ham United Karren Brady is awarded CBE in the prestigious list, as are TV presenter Nicholas Parsons and former Wimbledon champion Ann Jones.
Marcus Setchell, the doctor who oversaw the safe delivery of Prince George, is also recognised by the Queen.
Well-known Scots from all walks of life are honoured, including Glasgow-born venison farmer Nichola Fletcher, award-winning food-writer Lady Claire Macdonald and broadcaster Fiona Kennedy.
Some 1195 people are receiving an award and for the first time since the Order of the British Empire was founded in 1917, there are more women - 51% - on the list than men.
Ms Jenkins, who is known for work supporting the armed forces, said she is "incredibly humbled" to be awarded an OBE.
The 33-year-old Welsh mezzo-soprano has released 10 albums since 2004 and two have scooped prizes at the Classic Brits.
Ms Jenkins found a new fan base in the US last year when she was runner up in Dancing With The Stars, the American version of Strictly Come Dancing.
Earlier this year she ran the London Marathon, raising more than £25,000 for a cancer charity.
She said: "I am incredibly humbled to receive this great honour. To accept such an award after only a decade of service to music and charity comes as a wonderful surprise.
"I share this award with the charitable bodies I am so privileged to work with, especially to those brave servicemen and women who risk so much for us all on a daily basis."
Gavin and Stacey star Ruth Jones described her MBE as "proper tidy" and a "massive compliment".
The actress and writer got her big break on ITV's diet club drama Fat Friends in 2000, where she met co-star James Corden. The pair came up with the idea for Gavin and Stacey during breaks from filming.
The award-winning comedy made a star of Ms Jones, who co-wrote it and played the larger-than-life Nessa.
The 47-year-old said: "I had no idea it was coming. I just came home one night, opened the post and there it was: this letter telling me I was being put forward for it and being really strict about not telling anyone.
"And I'm quite obedient, so I didn't - except my husband who's really proud, and my dad, who's beside himself with excitement.
"Apparently great Uncle Leslie got an OBE in the 40s and Uncle Jack the fireman got one in the 60s. So I am keeping up with the Joneses."
Lynda Bellingham, best known for her long-running role in the Oxo TV adverts, said that being awarded an OBE was "a fantastic way to move forward" following a "tough year".
The 65-year-old Loose Women panellist, whose career has spanned 40 years, announced earlier this year that she had been diagnosed with cancer.
She said of her inclusion in the list for her charity work: "I am absolutely delighted and proud to receive this OBE.
"It has been a long and tough year but this award is just a fantastic way to move forward."
Other long-running TV stars being recognised by the Queen include Murder, She Wrote star Angela Lansbury and The Good Life actress Penelope Keith, who will both become Dames, and Grand Designs presenter Kevin McCloud, who receives a MBE.
TV and theatre legend Michael Crawford, who played Frank Spencer in Some Mothers Do 'Ave 'Em, said his CBE for services to children's charities is "the most wonderful surprise".
Marcus Setchell, who was the Queen's gynaecologist for two decades and oversaw the birth of Prince George, becomes Sir Marcus.
Meanwhile, Nichola Fletcher, originally from Glasgow, earns an MBE for services to the venison industry. Mrs Fletcher launched Fife's Reediehill Deer Farm with her husband in the 1970s and went on to become a world ambassador for the meat.
She said: "I am just thrilled that my work with venison should have been so honoured and it's great to be working in an area I feel so passionately about."
Lady Claire Macdonald, one of Scotland's best-known cooks and food writers has said she is humbled and thrilled to be hon-oured. She earned her reputation as a cook at the Isle of Skye's Kinloch Lodge, the luxury hotel run by her family for more than 40 years.
A keen fundraiser for Marie Curie Cancer Care, Lady Claire is awarded an OBE for services to the hospitality industry and in recog-nition of her charity work.
She said: "It is a feeling of dis-belief."
Aber-deen-shire-based Fiona Kenn-edy is hon-oured for her services to music and for her charity work. The broad-caster is the daughter of Scottish singer Calum Kennedy.