After making a second series, in 1999 Williams decided to leave the RSPB and pursue a full-time career in the media.

[8] In 2023, the BBC aired Iolo's Borderlands, a four-episode series presented by Williams about the wildlife of the Welsh Marches.

[13] The couple have two sons (Dewi and Tomos);[1] and had two rescue dogs, Ianto and Gwen, who have both appeared in some of his television series.

[14] Known for frequently wearing shorts for his work, he has, as a result, become a Welsh cult gay icon.

They compost all their food waste, and recycle everything else, whilst always eating organic and local produce.

As a result of this, in a 2011 World Wide Fund for Nature survey of carbon footprints of ecology personalities, Williams and his family were found to have a low rating of 1.81, compared to a Welsh average of 3.0.