Yes. But there is not a black and white answer to this question. As Susie and Otto point out, the "truth" is subjective in many instances.
Would you walk up to a total stranger and say, "Wow, you really have a huge nose. I honestly think that you should get some plastic surgery!" Barbra Streisand happens to like her nose and it has become part of her persona although I believe people early in her career wanted her to "fix" it.
Alcoholics need to be told they have problem, sometimes very bluntly, and that honesty may encourage them to get help. However, there are lots and lots of alcoholics who are aided and abetted every day by family members who cover for them.
Would you tell your married friend if her husband had an affair that you knew he really regretted and would never repeat if you knew that it would break up their marriage (assuming she thought she was happily married)? Telling her may be your version of honesty but may actually cause an enormous amount of unnecessary pain.
And the examples could go on and on . . . Sometimes it's a tough call.