Updated: August 28, 2020

The Time Tunnel is a 1966–1967 U.S. color science fiction TV series. The show was created and produced by Irwin Allen, his third science fiction television series. The show's main theme was Time Travel Adventure. The Time Tunnel was released by 20th Century Fox and broadcast on ABC. The show ran for one season of 30 episodes. Reruns currently air on AmericanLife TV Network and on Hulu. A pilot for a new series was produced in 2002, although it was not picked up.

Project Tic-Toc is a top secret U.S. government effort to build an experimental time machine known as "The Time Tunnel". The base for Project Tic-Toc was huge and located underground in the Arizona desert, with no visible entry. The only way in was a large secret panel; when it opened, a car could quickly go through the entrance. Once the panel closed, all anyone could see was ordinary desert. Tic-Toc base was a futuristic series of complexes 800 floors deep and employing over 36,000 people ("12 thousand people in each of those complexes"). It was under the command of Lt. General Heywood Kirk (Whit Bissell). The center of the base was The Time Tunnel control room where the Tunnel was located. In charge of operating the Tunnel were Dr. Ann McGregor (Lee Meriwether) and Dr. Raymond Swain (John Zaremba). The date at which it was operating was stated as 1968, which was two years into the future for the initial TV audience.

When the costs of the project approach those of the entire U.S. space program, United States Senator Leroy Clark (Gary Merrill) launches an investigation of the project. The Senator thinks that the Tunnel has cost too much money for too little reward. At his request the Senator is allowed to visit the project base and given a tour. Once he reaches the central control room the Senator explains his complaints to the project heads. The Senator then says that he wishes to close down the project as a waste of time and money that has not worked. None of the discussion mentions specifically why the project has not worked or any experiments sending inanimate objects through the Tunnel.

When no one else was around to observe, a key Time Tunnel scientist, young physicist Dr. Anthony Newman (James Darren), turns the machine on and sends himself back in time in an attempt to prove that the Time Tunnel project funds were not wasted. In so doing, Newman becomes "lost in time". The Time Tunnel top personnel quickly return, to see through the Tunnel that Newman is aboard the soon-to-sink Titanic. They can also see that he cannot escape before the sinking, and they cannot retrieve him.

In an attempt to rescue his younger friend, another key Tic-Toc scientist, Dr. Douglas Phillips (Robert Colbert), enters the Time Tunnel as well, carrying a newspaper describing the sinking to occur. There was no discussion about sending just the newspaper to the ship before risking another human becoming lost in time. Unconvinced, the captain of the Titanic throws the newspaper overboard.

However, the system was still being developed, and the Tunnel operations staff are never able to bring them home. As the series progresses, the two time travelers are swung from one period in history to another, allowing episodes to be set in the past and future. Each episode (up to episode 24) begins with the following narration (which Dick Tufeld voiced):