Ode to a Nightingale by John Keats
Rabbit, Run by John Updike
The name of Rabbit's mistress in this book is a bit of an ironic twist on the Book of Ruth. Ruth Leonard is an atheist and ex-prostitute who demands that Rabbit leave his wife and marry her. Naturally, Rabbit runs, but you already saw that coming.
The Book of Ruth by Jane Hamilton
The Threepenny Opera by Kurt Weill and Bertolt Brecht
Men Are from Israel, Women Are from Moab by Norm Wakefield and Jody Brolsma
Pride and Prejudice by Jane Austen
Okay, hear us out on this one. No, the novel doesn't have any explicit ties to Ruth, but it does tell the story of a woman who would love for nothing more than her daughter to marry "a prominent rich man" so that she can have security and a future as a wife. We're pretty sure Boaz would be invited to tea at Longbourn.