The building, in Bearwood Road, has been modernised and is now offering extended opening hours.
Customers can now use an open-plan till at the retail counter, where Post Office services are available during shop opening hours.
The branch is open Monday to Friday from 6.30am to 7.30pm; on Saturday between 7am and 7.30pm; and on Sunday from 8am to 4pm.
This offers customers an extra 61 hours a week, including all day Sunday and Wednesday and Saturday afternoons.
Mr Redwood, MP for Wokingham, said: “I am delighted to be here today to congratulate new operator Rajesh Dole on his hard work and to formally declare the new Barkham Post Office open.
“It is vital to the community around Barkham and I’m sure the new improved office, and the longer opening hours, will be warmly welcomed by all of my constituents.”
Rajesh and Ashu Dole bought Barkham Village Store in January and immediately started plans to refurbish the Post Office and the newsagents, off-licence and grocers store.
Mr Dole said: “I was delighted to have the opportunity to open the new-look branch. Customers are very happy with the changes. The layout of the branch is far better than the previous layout. Customers think it is a great improvement.”