Nationwide's logo will appear on the front cover of the section, either side of the title, as well as on the buyers' section inside.
According to the newspaper's publisher Daily Mail and General Trust, the Personal Finance section is a key part of the newspaper and of "enormous interest to readers of The Mail on Sunday".
Personal Finance is printed in-line with the rest of the newspaper at Harmsworth Quays, the Daily Mail's own printer.
The deal was brokered by Paul Burke and Nigel D’Cruze at Mail Connected, Christie Brock, account director at MPG Global Media Agency and Chris Ladd, marketing planning manager at Nationwide.
Brock said: "The Personal Finance section of The Mail on Sunday provides the perfect editorial environment for Nationwide and this deal is an ideal way for them to reach a targeted audience engaged in the world of personal finance.
"This will allow Nationwide the flexibility to deliver their brand message or a specific product message over the next year."