Echo is a middle grade historical fiction novel written by Pam Muñoz Ryan, illustrated by Dinara Mirtalipova, and published by Scholastic Press in 2015.

It is set in Germany and America, primarily in the years leading up to World War II and details how a mysterious harmonica and the music it makes ties together the lives of three children: Friedrich Schmidt, an intern at the Hohner factory; Mike Flannery, an orphan in Philadelphia; and Ivy Maria Lopez, daughter of migrant farm workers.

After the heir arrives, the princesses are informed of their royal birth and prepare to rejoin their family; however, rather than releasing them, the witch curses the girls: A messenger brought you about.

When the story resumes almost 70 years later, the harmonica is discovered in a storage room of the Hohner factory by Friedrich Schmidt; it is in a box marked "Marine Band/1896" with a matching cover plate for export to the United States and is distinguished by a red script letter M on the pearwood comb.

The novel traces the journey of the harmonica from Friedrich to two orphan brothers, Mike and Frankie Flannery in Philadelphia, and then to a migrant worker's daughter, Ivy Maria Lopez in California.

Each child has unusual musical talent and faces unique challenges in their lives: Friedrich, who dreams of being a conductor, was forced to drop out of school after the bullying that resulted from his appearance, and is threatened with sterilization in Nazi Germany; Mike, a talented pianist, wishes to join Albert N. Hoxie's Philadelphia Harmonica Band of Wizards as a way to escape the orphanage and poverty while taking care of his younger brother, Frankie; and Ivy, just discovering her talent and love for music, is forced to attend a segregated school while helping her father and mother take care of the Yamamoto family farm after the Yamamotos were forced into internment camps after the attack on Pearl Harbor.

Set in October 1935, Friedrich is a German boy afflicted with a birthmark on his face that people of his town consider a deformity.

Mr. Howard eventually reveals that Mrs. Sturbridge did not want to adopt a child at all, but in fact had to or she would lose her family fortune, per a clause in her father's will.

Part two ends as Mike and Frankie pack their bags and plan to run away to New York City so they won't be sent back to the orphanage and split up.

The third and last part of the book begins in December 1942 and follows the story of Ivy Maria Lopez, a Mexican-American girl living in California.

In 2016, the American Library Association named Echo to its list of Newbery Honor winners, alongside Kimberly Brubaker Bradley's The War That Saved My Life and Victoria Jamieson's Roller Girl.