Through the Keyhole is a light-hearted BBC (originally ITV) panel game, where panelists have to attempt to identify the celebrity who lives in a house, after they are given a video tour of it. It has been running since 1983, though not continuously.

At the start of each episode, David Frost, the main presenter, introduces the panel of three celebrities, who have to deduce the identity of the owners of the houses (two houses are featured in each episode). Then he hands over to Catherine Gee (Loyd Grossman until the early 2000s) at the first house.

Loyd or Catherine then take the viewer on a tour of the house, showing the various rooms, and highlighting things that hint at the owner of the house, and possibly some red herrings as well. After this, they sum up the 'evidence', then hand back to the David in the studio (with the catch phrase "Who lives in a house like this? David, it's over to you").

The audience at home, and the studio audience are shown who the owner (or owners) of the house are (although members of the audience at home can look away at that point). Then the panel take it in turns to guess the owner of the house. They usually start by making broad conclusions about the owner, such as gender, then get more specific as things progress. They are aided by David, who gives them hints as to how close they are, and the audience, who applaud when the panellist is on the right lines.

Finally, either the panellists guess correctly, or David has to tell the panel who the owner is. Then usually David interviews the owner of the house, although occasionally a pre-recorded interview with Loyd is played instead, at the house. After the interview, the same pattern is followed with the second house of the episode.

The show has just recorded another series (2005) which is series 7 and is set to continue through to 2007 on BBC 2. Series 7 will start transmission on 27th Feb 2006.