The big announcement comes as Meghan and Harry, 34, grow closer to welcoming their first child. Along with Smart Works, the Palace has announced official roles for Meghan with the National Theatre, the Association of Commonwealth Universities, Smart Works, and Mayhew, an animal welfare organization.
Meghan will now be patron The National Theatre, the Association of Commonwealth Universities, women's charity Smart Works and animal charity Mayhew. Meghan on Thursday has become patron of the Smart Works charity that supports unemployed women to return to work.
Markle, who starred on the TV show "Suits" before she married Prince Harry, was thought to have recently invited Rufus Norris, the artistic director of the theatre, for a private meeting at the Palace.
The Queen previously was patron of the National Theatre and the ACU, but has now passed them on to the duchess.
"Meghan has so much on her plate, between being pregnant and dealing with the public backlash, and she's finding the whole situation incredibly stressful", a royal insider explained.
Kate Middleton, Markle's sister-in-law, received her first royal patronage for the Royal Foundation in October 2011, six months after she tied the knot with Prince William, Duke of Cambridge. It also emerged during her visit that Meghan has been there several times - and even gave some women coaching before a job interview.
Meghan Markle has four new jobs.
Meghan is a big animal lover - she and Harry greeted the dogs of Ireland's President Michael Higgins and wife Sabina in July a year ago.
Then just weeks ago sources claimed Meghan, 37, was "fed-up" of not being able to "stand up for herself" as the demands of royal protocol dictate she keeps a dignified silence amid rumours of tension between the sisters-in-law.
She said: "It's not just donating your clothes and seeing where they land, but really being a part of each other's success stories as women, right?"
"Members of the royal family can use their patronages to shape their legacy as members of the royal family", Murphy told ABC News.
He added: "The Duchess shares our deeply-held conviction that theatre has the power to bring together people from all communities and walks of life".