The purpose of a DNS server is to enable people and applications to lookup records in DNS tables. Most DNS servers are now private, meaning that they are configured to only provide service to the people and organizations who own and maintain them.

A few domain name servers on the Internet provide DNS resolutions for anyone who requests it of them. These are known as "Public DNS Servers."

Most public DNS servers are public on purpose. Below is a list of Public DNS Servers.

Google
8.8.8.8
8.8.4.4

Level 3 Communications (Broomfield, CO, US)
4.2.2.1
4.2.2.2
4.2.2.3
4.2.2.4
4.2.2.5
4.2.2.6

CenturyLink (Fomerly UTS, Sprint, Embarq, CenturyTel)
199.44.2.10 (Tallahassee, FL)
207.14.235.234
67.238.98.162
74.4.19.188

Verizon (Reston, VA, US)
151.197.0.38
151.197.0.39
151.202.0.84
151.202.0.85
151.202.0.85
151.203.0.84
151.203.0.85
199.45.32.37
199.45.32.38
199.45.32.40
199.45.32.43

GTE (Irving, TX, US)
192.76.85.133
206.124.64.1

One Connect IP (Albuquerque, NM, US)
67.138.54.100

OpenDNS (San Francisco, CA, US)
208.67.222.222
208.67.220.220

Comodo SecureDNS (Jersey City, NJ)
156.154.70.22
156.154.71.22

Exetel (Sydney, AU)
220.233.167.31

VRx Network Services (New York, NY, US)
199.166.31.3

SpeakEasy (Seattle, WA, US)
66.93.87.2
216.231.41.2
216.254.95.2
64.81.45.2
64.81.111.2
64.81.127.2
64.81.79.2
64.81.159.2
66.92.64.2
66.92.224.2
66.92.159.2
64.81.79.2
64.81.159.2
64.81.127.2
64.81.45.2
216.27.175.2
66.92.159.2
66.93.87.2

Sprintlink (Overland Park, KS, US)
199.2.252.10
204.97.212.10
204.117.214.10

Cisco (San Jose, CA, US)
64.102.255.44
128.107.241.185

OpenNIC
202.83.95.227 (au)
119.31.230.42(au)
178.63.26.173 (de)
217.79.186.148 (de)
27.110.120.30(nz)
89.16.173.11 (uk)
69.164.208.50 (us)
216.87.84.211(us)
2001:470:8388:10:0:100:53:20 (us)
2001:470:1f10:c6::2 (us)