In 2014, Mould co-hosted ITV's I Never Knew That About Britain alongside Paul Martin and Suzannah Lipscomb. He has also appeared as a science expert on The Alan Titchmarsh Show, The One Show and Blue Peter.
Mould's YouTube video, in which he demonstrated the phenomenon of self-siphoning beads and proposed an explanation, brought the problem to the attention of academics John Biggins and Mark Warner of Cambridge University, who published their findings about what has now been called "chain fountain" in Proceedings of the Royal Society A. It's sometimes called 'The Mould Effect' in some internet articles.
Between 2008 and 2010, Mould performed three geeky sketch shows at the Edinburgh Festival Fringe with Gemma Arrowsmith. Since 2011, Steve has performed live science comedy as part of the comedic trio Festival of the Spoken Nerd, with mathematician Matt Parker and physicist songstress Helen Arney. Festival of the Spoken Nerd has performed at theatres, science and arts festivals.