Who Do You Think You Are? (10 p.m., TLC) - Season 10 starts with Mandy Moore (“This Is Us”) tracing her genealogy to Australia. Moore is touched by the courage of those who made the journey to America and by the sacrifice of those who were left behind.
Also on . . .
The Great Christmas Light Fight (8 p.m., ABC) - Tonight’s show features homes in Kokomo, Indiana; Weirsdale, Florida; Grand Rivers, Kentucky; Clifton, Ohio; Rockaway Beach, New York; Fox River Grover, Illinois; and San Francisco, California.
Holiday Baking Championship (9 p.m., Food) - The five bakers have to update traditional rugelach with unexpected flavors like cardamom, grapefruit, guava paste, peanut butter or chai.
Pop Up Santa Holiday Special (9:30 p.m., Freeform) - A special celebrating the spirit of the holiday season through heartwarming moments like a home giveaway, a baby shower at a military base and a celebration for kids at Children’s Hospital in Los Angeles.
Christmas Cookie Challenge (10 p.m., Food) - The cookie makers use traditional nesting dolls as inspiration to make six cookies of the same design that get progressively smaller.