In microsoft visio 2010 professional and better you are able to select the footer by double-clicking in the blank area at the end of your document. Once you've double-clicked on the footer, you need to see the First Page Footer section like the example shown below.

Once in the footer section type your footer. Automatically, the footer is on all pages of your document. If you want to alter the header on different pages, uncheck the Different First Page option in the Ribbon. Also, within the microsoft office 2013 professional plus Tools portion of the Ribbon you can adjust the footer size and if you want it different on odd and even pages.

When you are done modifying the footer you may either double-click on the body from the document or click the Close Header and Footer button on the Ribbon.