Tim Martin's company sold the Red Lion, in Heanor, and the Twitchel Inn, in Long Eaton, to Hawthorn Leisure, which currently owns more than 300 pubs across the UK, in November 2015.
Both pubs opened their doors to the public on Sunday having undergone a four-day refurbishment.
Wetherspoon's scrapped Sunday roasts at its pubs in February, saying it had to make "the right decisions for the company".
A spokesperson for the company said JDW wanted to focus on its core menu.
However, the move proved controversial, with many customers taking to social media to air their anger.
Gerry Carroll, chief executive of Hawthorn Leisure, told the Derby Telegraph: "The opening and re-introduction of the Sunday lunch is only the start of a host of activities, events and deals that we have planned for the coming months, all set to deliver a great proposition for locals."
Wetherspoon became the subject of praise by animal rights charity PETA in March when it began highlighting vegetarian and vegan dishes on separate menus across its estate.