The Linda McCartney factory, in Fakenham, is to be expanded by the company's American owners Hain Daniels.
Marketing director Nigel Parrot said as more consumers eat less meat "we need to expand that factory to meet our future demand".
Investment on the Holt Road site is expected to be completed by the autumn.
"The investment involves the installation of new production facilities and upgrading existing plant and equipment in order to meet growing demand for the extensive range of meat-free products, crumbles and hot desserts made at the Fakenham site," said chief executive Rob Burnett.
"It's great news for the local economy as we will be able to provide long-term employment and excellent career prospects for people."
The decision to invest in the factory reflects a turnaround for the site, which was on the brink of closure four years ago.
"The brand is growing at about 20% and food growth at about 4%," said the Fakenham site's group operations director David Betts-Grey.
"We think that is going to continue for many years so we're sure all the new jobs will be pretty secure for the long term."
Up to 150 new jobs are to be created in Norfolk following a multi-million pound investment at a frozen food factory that specialises in meat-free produce.