Do I need a PPL license for a CPL license?
Yes, with a couple of exceptions. FAR 61.123 contains the requirements for a commercial certificate, while 61.153 contains the requirements for an ATP certificate.

FAR 61.123(h) states than an applicant must:


  Hold at least a private pilot certificate issued under this part or meet the requirements of §61.73


FAR 61.73 refers to the option for military pilots to apply for an FAA certificate based on their military qualifications. For non-military pilots, the commercial certificate can only be earned after obtaining the private pilot certificate.

FAR 61.153(d) includes the ability to use a foreign commercial or ATP certificate as a prerequisite. An applicant must:


  Meet at least one of the following requirements:
  
  (1) Holds a commercial pilot certificate with an instrument rating issued under this part;
  
  (2) Meet the military experience requirements under §61.73 of this part to qualify for a commercial pilot certificate, and an instrument rating if the person is a rated military pilot or former rated military pilot of an Armed Force of the United States; or
  
  (3) Holds either a foreign airline transport pilot license with instrument privileges, or a foreign commercial pilot license with an instrument rating, that—
  
  
    (i) Was issued by a contracting State to the Convention on International Civil Aviation; and
    
    (ii) Contains no geographical limitations.