Trouble With Lichen (published 1960) is a science fiction novel by John Wyndham. It is intended as a social satire, opinion varies as to its quality. It is not generally regarded as quite one of Wyndham's best novels, but some consider it an interesting and entertaining piece nevertheless.

The plot concerns a young woman biochemist who discovers that a chemical extracted from an unusual strain of lichen (hence the title) can be used to retard the ageing process, enabling people to live to around 200-300 years. Wyndham speculates how society would deal with this prospect.