After the Soviet invasion in 1968, he and his family left then-Communist Czechoslovakia for Canada. Upon arriving at Victoria, British Columbia, his father found work as a structural engineer and his mother found work as a nurse.
Nykl has appeared heavily in Vancouver and Prague in dozens of theater, film and television productions. Known for his versatility and depth as an actor, he has also produced theatre and film projects, and in 1994 he co-founded Prague's Misery Loves Company Theatre with Richard Toth and Ewan McLaren.
He is known to science fiction fans as the recurring Stargate Atlantis character of Dr. Radek Zelenka, a Czech scientist on Earth's expedition to the "lost city" of Atlantis. His character often provides a foil to the main scientists, who forget the limits of their situation.