1. In Reports, open the template and go to the Format tab and highlight Sort
  2. Pull constituent name in the available sort fields
Note: Not all reports have the Sort feature.

Alternate solution:
  1. Create a query for the report (or use an output query from the report)
  2. Output constituent name in the query
  3. Sort by constituent name
  4. Save the query
  5. Use this query in the report