The movie, described as 'a modern fairy tale', has already begun filming and will star Alice St Clair and Dan Amboyer as a young Kate and William.
American director Yelen, who also produced the CBS film The Royal Romance of Charles and Diana in 1982, claimed that Princess Diana inspired her to pen the script.
"[It's] a very personal story. In a way it's my tribute to [Diana] as well as a tribute to the young couple," Yelen told the Daily Mail.
Yelen said that she wrote the film's script in under two weeks after realising that William had presented Kate with his mother's ring.
Lifetime produced its own story of the royal couple's romance in the television film William & Kate,, which starred Camilla Luddington and Nico Evers-Swindell.
Prince William married Kate Middleton last month at Westminster Abbey in a ceremony watched by around 300 million people worldwide.
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Watch Prince William and Kate kiss on the Buckingham Palace balcony below: