Charles was born to James Mathews (died 1804), a Wesleyan Methodist bookseller, printer, and pharmacist on the Strand, who also served as minister in one of the Countess of Huntingdon's chapels.

During his youth, Charles met the actor Robert William Elliston; after attending the Drury Lane theatre, he was utterly fascinated by that world.

The following year his father allowed him to take up acting in Dublin, writing, "Charles, there are your indentures, and there are twenty guineas; I do not approve of the stage, but I will not oppose your wishes.

At any time hereafter, should you feel inclined to turn to an honest calling, there are twenty guineas more, if you send for them, and your father's house is open to you."

[2] For several years Mathews took bit parts, but on 15 May 1803 he made his first London appearance at the Haymarket, as Jabel in Cumberland's The Jew and as Lingo in The Agreeable Surprise.

Leigh Hunt wrote that his table entertainments "for the richness and variety of his humour, were as good as half a dozen plays distilled.

In his next show, A Trip to America, Mathews sang a version of the popular slave freedom song, "Possum Up a Gum Tree", performing in dialect and possibly in blackface.