Oprah Winfrey is donating £12 million in support of African American history.

The chat show legend has announced her pledge to help build the Smithsonian institution's forthcoming National Museum of African American History and Culture in Washington D.C.

The 59-year-old star will have the facility's 350-seat theatre named after her as a special thanks.

According to The Hollywood Reporter, Oprah said: ''I am so proud of African American history and its contributions to our nation as a whole. I am deeply appreciative of those who paved the path for me and all who follow in their footsteps.

''By investing in this museum, I want to help ensure that we both honour and preserve our culture and history, so that the stories of who we are will live on for generations to come.''

Oprah - who has been a member of the museum's advisory council since 2004 - previously gave $1 million to the museum in 2007, which takes her total up to $13 million - a sum only matched by the CEO's own donation.

Lonnie G. Bunch III, the museum's founding director, enthused: ''We are inspired and profoundly grateful for Ms. Winfrey's generosity at this important time. Her gifts will forever be associated with harnessing the power of art and creative expression to build bridges between cultures and enrich people's lives.''

The National Museum of African American History and Culture is currently under construction and is set to open in late 2015.