OWN's start date has been delayed twice and its cost has reportedly swollen to $189m (£121m).
Among the programmes scheduled is a reality show starring the Duchess of York, Sarah Ferguson.
Winfrey has built up a huge fan base during 25 years as the host of the syndicated Oprah Winfrey Show.
The programmes on the new station have a focus on empowerment, improvement, positivity aimed mainly at women, who are Ms Winfrey's core audience.
"I wanted to build a network which empowers you, the viewer, to turn your dreams into reality," Ms Winfrey said on a preview programme that launched the network on Saturday.
One of the programmes offered will be a reality show in which 10 finalists from thousands of applicants will compete for the chance to host their own TV show.
There will also be a programme called Why Not?, hosted by Canadian country singer Shania Twain.