His mother is US citizen Eleanor Darragh.
His father is Cuban citizen Rafael B. Cruz. (naturalized as a U.S. citizen in 2005)
Eleanor Darragh and Rafael B. Cruz were residents of Canada for at least four years from 1970, possibly earlier, until 1974. They conducted business there as Rafael B. Cruz and Associates, Ltd.
It appears he is in law a natural born citizen of Canada (Canadian Citizenship Act, R.S.C. 1970, c. C-19, s. 5(1,3))
Revised Statutes of Canada 1970:
Accessed at:
http://ia700401.us.archive.org/10/items/revisedstatutes197001uoft/revisedstatutes197001uoft.pdf
Biographical info:
http://www.dallasnews.com/news/politics/headlines/20120428-senate-candidate-ted-cruz-aims-to-pick-up-mantle-of-reagan.ece
http://www.dallasnews.com/news/state/headlines/20111025-a-tighter-lipped-cruz-lets-others-fill-in-blanks-on-cuban-fathers-exodus.ece
http://latino.foxnews.com/latino/politics/2013/04/08/ted-cruz-father-and-inspiration-talks-about-latinos-conservatives-and-american/
http://latino.foxnews.com/latino/politics/2012/04/15/ted-cruz-texas-answer-to-marco-rubio/
http://www.chron.com/news/politics/article/Cruz-s-life-defies-simplification-3946523.php