Johnny Ball (born May 23, 1938) is a British television personality. He was a regular fixture on children's television in the 1970s and 1980s, presenting several series of popular science and technology programs intended for children (including Think of a Number; Think Again; Think Backwards; Think...This Way and Johnny Ball Reveals All). He was also one of the hosts of infant education programme Play School. All of these shows (except the ITV programme ...Reveals All) appeared on the BBC.

He is the father of former BBC Radio 1 DJ and TV host Zoë Ball.

In July, 2004 he was named in the Radio Times list of the top 40 most eccentric TV presenters of all time. He was certainly one of the best, with a whole generation of children enjoying the way he could explain complicated scientific and mathematical phenomena in such a straightforward and unpatronising way, and with the aid of a few appalling puns ("I'm a mystic! And here's me stick!").