The Belgian second-tier side have also negotiated an option to buy the 23-year-old midfielder next summer for a six-figure fee.
Henderson has made 56 appearances for Hibs since making the switch from Celtic in January 2022, but has struggled for regular game-time this season, making only making one appearance in all competitions.
Hibs manager Lee Johnson commented: “We wish Hendo all the best during his loan spell in Belgium. This gives him the opportunity to gain regular game-time as K.V. Oostende look to bounce straight back into the top-tier of Belgian football.”
KV Oostende sporting director Nils Vanneste added: “At Celtic, Henderson was considered a very promising youngster. He showed great things, but the big breakthrough just didn't come. At Hibernian, which finished fourth in the first division last season, he played 30 times last season. He is a player who has to teach us the much needed dose of creativity. With his footballing ability and insight, he should be able to create opportunities for his fellow players. So he is the type of player we absolutely needed.”