When Calls the Heart is a Western drama television series inspired by Janette Oke's book of the same name from her Canadian West series and developed by Michael Landon Jr. The series began airing on the Hallmark Channel in the United States on January 11, 2014, and on Super Channel in Canada on April 16, 2014.

The series originated from a two-hour television movie pilot in October 2013, starring Poppy Drayton as young teacher Elizabeth Thatcher and Stephen Amell as North-West Mounted Police officer Wynn Delaney. In the television series, Erin Krakow plays the lead role alongside an ensemble cast.

On March 21, 2018, Hallmark renewed the series for a sixth season. The season premiered with a two-hour Christmas special that was broadcast as part of Hallmark's Countdown to Christmas event, and was to continue for a 10-episode run starting in February 2019. However, due to the 2019 college admissions bribery scandal involving Lori Loughlin and her subsequent removal from all Hallmark properties, the season was put on a "retooling" hiatus and resumed in May to conclude in June, with Loughlin's scenes edited out.

On February 22, 2023, ahead of the tenth season premiere, the series was renewed for an eleventh season, which premiered on April 7, 2024. On May 10, 2024, the series was renewed for season twelve, which began production in July 2024.