Find someone's cell phone number by using the person's name. There are free, online cell phone listings people can voluntarily opt into that could have the information you need. If not, use a paid service to find out information about someone, such as his cell phone number.
Navigate to Find Cell Phone Numbers, a free cell phone directory. Look up anyone in the directory by using his name to find his cell phone number. The directory works by requiring that you add your own number first. The directory also lets you start with a number and get a name.
Navigate to Cell Phone Search. In the appropriate fields, enter the first and last name, as well as the city and state, of the person you're looking for. Click "Search" and you'll be taken to a page that has minor location information about the person. Use a credit card to purchase his cell phone number.
Visit the Cellpages site. Cellpages is an opt-in free cell phone directory. Search by number, name or geographical location. The site asks you for your own phone number before giving you the one for the person you want, which is what "opt in" means. The voluntary nature of the directory is what keeps it free.