Is there any way for an undocumented immigrant ( 18 years old ) can immigrate to another country and be legal ?

There are many countries that generally do not care about the immigration status of an immigration applicant in another country. The United States for one does not care, and we have immigrated many people to the States whose immigration statuses were not legal in a third country. More of an impediment is probably your age and possible lack of high education and working skills if attempting to immigrate through employment.  You would have to speak with people who know about the immigration rules of other countries on your specific circumstances. We unfortunately do not.  Due to the limitations of the Lawyers.com Forums, Alan Lee, Esq.'s (the "Firm") participation in responding to questions posted herein does not constitute legal advice, nor legal representation of the person or entity posting a question. No Attorney/Client relationship is or shall be construed to be created hereby. The information provided herein by the Firm is general, and requires that the poster obtain specific legal advice from an attorney. The poster shall not rely upon the information provided herein as legal advice nor as the basis for making any decisions of legal consequence.