You should never refer to yourself in the first person in your CV. While most of your CV can omit any references and use point form of the tasks, skills and technologies (for example) you used in a job, using the third person is something you can do in your executive summary.
For example, my CV starts with the following:
Jane S is an IT professional with over 19 years experience as a data specialist, solution architect, analyst and software developer. She has worked in various industry sectors including the financial, mining, manufacturing and telecommunications industries, and for local, state and federal government departments.
Speaking in the third person can give an air of authority when talking about yourself, as it's like a formal introduction someone else may give. Think of it as how you would like to be introduced as a keynote speaker at a big conference :)