He also wrote popular children's books including The Great Jelly of London, The Hopping Basket, and The Train to Yesterday.

In 1949 he joined The Observer, contributing a fortnightly column entitled "Oddly Enough" until 1966, when he was succeeded by Michael Frayn,[5] who was an admirer of his work.

[7] In general his pieces take the form of whimsical ponderings; some are based in real-life incidents, often involving his friend Harblow.

[8] His pieces are sometimes poems,[citation needed] and sometimes written in novel forms of language, such as the Romance-eschewing Anglish,[9] or that of a toy 19-letter pipewipen (typewriter).

[10] Other articles were extended flights of fancy, such as "The Unthinkable Carrier"[11] based on the idea of cutting Britain free of the Earth's crust so that it could float around the oceans and guarantee world peace, with the Isle of Wight kept in place by a tow chain.

[12] Several of his pieces touched on the invented philosophical movement of Resistentialism,[13] a concept that probably owes some of its force to the contempt that Jennings—a devout Catholic—felt for the intellectual fashion he was parodying.