The 33-year-old mezzo-soprano said she was “incredibly humbled” at the award in the New Year Honours, which she wishes to share with the organisations with which she has worked.
The Neath-born star has released 10 albums since breaking on to the music scene in 2004, including two winners of the best album prize at the Classic Brits.
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.”
Jenkins proved herself as a chorister at school before winning a scholarship to study at the Royal Academy of Music, then becoming a teacher and model until landing a record deal. She has performed for royalty, had cameo TV roles, toured the UK and raised more than £25,000 for a cancer charity by running the London Marathon this year.
She joined actress Penelope Keith in toasting the good life after she became a dame for her services to the arts and to charity. Having played well-to-do characters in sitcoms such as To The Manor Born, the 73-year-old now has a title of her own.
Dame Penelope developed an interest in acting while at boarding school and joined the Royal Shakespeare Company in her 20s before going on to have minor TV roles in shows such as The Avengers.
But it was in the 1970s that she became a familiar face on TV starring as Margot Leadbetter in The Good Life, before playing Lady Audrey fforbes-Hamilton in To The Manor Born. She has worked with the Actors’ Benevolent Fund, the National Trust and the Human Embryology and Fertilisation Authority.