The 2009–10 Japan Junior Figure Skating Championships were the Japanese National Championships for the junior level for the 2009–10 season. They were the 78th Japan Junior Championships. They took place at the Shinyokohama Skate Center in Yokohama from November 21 through 23, 2009. The results of this competition were used to choose the Japanese team to the 2010 World Junior Championships.
The following skaters placed high enough at Novice Nationals and so were invited to compete at Junior Nationals: Shoma Uno (1st in novice, 3rd in junior), Shuu Nakamura (2nd in novice, 23rd in junior) for the men; and Ayana Yasuhara (1st in novice, 28th in junior), Risa Shoji (2nd in novice, 10th in junior), Riona Kato (3rd in novice, 7th in junior), and Satoko Miyahara (4th in novice, 4th in junior) for the ladies.