I love making tidy lists, so here’s a clear breakdown of the clans in 'Naruto' that are known for genuine kekkei genkai and the characters who wield them.
Uchiha — Sharingan (and Mangekyō variants): big names include Madara, Itachi, Sasuke, Obito and Shisui. Hyūga — Byakugan: Hiashi, Hinata, Neji, Hanabi. Senju — Mokuton (Wood Release): Hashirama Senju is the prime example (and later users like Yamato gained it through Hashirama’s cells). Kaguya (the clan behind Kimimaro) — Shikotsumyaku (cursed bone/bone manipulation): Kimimaro is the standout.
Yuki — Hyōton (Ice Release): Haku. The Ōtsutsuki line is the ancient source for several ocular kekkei genkai (Kaguya, Hagoromo’s lineage, Toneri later on). Beyond these clan-wide traits, many kekkei genkai in the series are individual or rare: Mei Terumi’s Lava and Boil Releases, Onoki’s Dust Release (a kekkei tōta), and other unique nature fusions often appear tied to bloodlines or special circumstances rather than entire modern clans. I still get a kick tracing how a single family trait turns into a major plot device in the world of 'Naruto'.