Listing a high school degree is fine when the client is a recent high school graduate. There's really no other time when including such information becomes relevant.

And this rings true for seasoned professionals.

Envision this scenario:  a sales and marketing executive just put the final touches on his resume.

His list of education includes a bachelor’s degree, an associate’s degree, and a high school diploma.

Will this executive be hired or interviewed because he graduated from high school? Or is it far more likely that he'll be hired because he completed the Bachelor's degree?

There comes a time when you MUST eliminate certain education from the resumes you write because it no longer plays a role in what's being pursued.

One could argue that once a professional satisfies the requirements and receives a college degree, the high school diploma is implied.

Is there ever a time when including an HS diploma is a good idea for seasoned professionals? Yes, actually, there is. One scenario may be: when a hiring manager graduated from the same high school as the job applicant. Including mention of the same high school could give your client an added shot at an interview. There's no certainly of course.