Joshua Alder (7 April 1792 – 21 January 1867)[1] was a British cheesemonger and amateur zoologist and malacologist.

[3] From 1841 to 1857 Alder was a tenant at 5 Ravensworth Terrace in the Summerhill area of Newcastle upon Tyne, which he shared with his sister Mary, a woman of independent means, and their two female servants.

[2] In 1863 he wrote to his co-author Albany Hancock of his relief at being awarded a pension of £70 from the civil list by Lord Palmerston at the behest of his scientific colleagues, allowing him to resume his research.

[2] An obituary noted that he was "everywhere accompanied" by his sister, who "assisted him in his studies and was, in short, essential to his life and health".

[2] Alder is profiled in the first episode of the second series of A House Through Time, first shown in April 2019.