I got a question for you: Khan Noonien Singh, commonly shortened to Khan, is a fictional character in the Star Trek science fiction franchise. The character first appeared in the Star Trek: The Original Series episode "Space Seed" (1967), and was portrayed by Ricardo Montalban who reprised his role in the 1982 film Star Trek II: The Wrath of Khan. In the 2013 film Star Trek Into Darkness, he is played by Benedict Cumberbatch.

Based on this passage, who played khan in the original star trek series?
Let's think first:
The relevant sentence in the passage is: The character first appeared in the Star Trek: The Original Series episode "Space Seed" (1967), and was portrayed by Ricardo Montalban who reprised his role in the 1982 film Star Trek II: The Wrath of Khan.
Therefore, the answer is Ricardo Montalban.