Q. Which font should I use in my papers if I'm using the APA Style rules?

APA 6th Edition

The preferred font within APA Style is Times New Roman (12 pt.) (American Psychological Association, 2010, p. 228).

Reference

American Psychological Association. (2010). Publication manual of the American Psychological Association (6th ed.). Washington, DC: Author. 

APA 7th Edition

Although the APA does not limit writers to a particular font, writers should format their paper using an accessible font and maintain this formatting throughout the paper for a consistent, readable text (American Psychological Association, 2020, p. 44). Generally, 10 or 11-point san serif font (Calibri, Arial, or Lucida Sans Unicode) or 11 or 12-point serif font (Georgia or Times New Roman) are standard choices, but please check with your instructor or program regarding their preferences or requirements regarding font.

Reference

American Psychological Association. (2020). Publication manual of the American Psychological Association (7th ed.). https://doi.org/10.1037/0000165-000