In which magazine was Oliver Twist first serialized?

Oliver Twist was first serialised in Bentley's Miscellany.

The novel began appearing in the monthly literary magazine in February 1837 and concluded in April 1839. Charles Dickens was closely connected with the publication: its founder, Richard Bentley, had invited him to become its first editor. Dickens published Oliver Twist under his familiar pseudonym, “Boz,” while the magazine carried George Cruikshank's illustrations alongside the instalments.

The serial ran for 24 monthly parts, although publication did not occur every month; there was no issue in June 1837, and several other gaps occurred later. The work was originally intended to form part of Dickens's projected serial The Mudfog Papers. It soon became a separate novel about an orphan who escapes a workhouse and encounters Fagin's criminal network in London.

The book edition appeared in three volumes in 1838, six months before the serialisation had finished. That timing can cause confusion: Richard Bentley published the book, but Bentley's Miscellany was the magazine in which the story first appeared. The Cornhill Magazine, All the Year Round, and Household Words were associated with other writers or Dickens projects.