The new loaf (rsp: £1.34), which rolls out to Asda this week and other retailers over the next two months, is made from 50% oats and 50% wheatflour.
Premier claimed oats were currently "in vogue" among consumers and said Hearty Oats would achieve success because people "easily understood" their health benefits and slow energy release credentials.
The newcomer will line up against Kingsmill's Oatilicious, which launched in January. Unlike Hearty Oats, which contains whole oat pieces, Oatilicious has a smooth texture.
Hovis boss Jon Goldstone claimed consumers would prefer the taste of the Hovis product, following a blind taste test in which 70% of participants voted in favour of the Hearty Oats bread.
"This has been two years in the making and we expect it to be the biggest fmcg launch of the year," said Goldstone.
Premier is supporting it with a £5m spend, including a week-long TV push from 5 June.