Length of Ph. D. Application CV for Mid-Career Professionals

I am applying for a Ph. D. program after a 10 year career of secondary classroom teaching - I have held several positions in that time should I cut some of these teaching experiences out to make my CV fit one page

Rather than cutting them out, why not list them, but omit descriptions, e.g.,

• 2018 - 2020 Department Head, School, City
• 2012 - 2018 Senior XYZ, School, City
• 2000 - 2012 XYZ, School, City

The descriptions can be pushed elsewhere, e.g., into an opening sentence. Alternatively, if you were at the same school, then something like:

• 2000 - 2020 School, City

  I concluded my teaching career as Department Head (2018-2020), having served as Senior XYZ (2012-2018) and XYZ (2000-2012). Blah, blah, blah.

Even if you weren't at the same school, you could use something similar, e.g.,

• 2000 - 2020 Secondary classroom teaching

  I concluded my teaching career as Department Head (2018-2020), School, City, having served as Senior XYZ (2012-2018), School, City and XYZ (2000-2012), School, City. Blah, blah, blah.

The key idea is to include all positions. Don't omit material, gaps don't look good. Compress instead.