Cognomen Kajohnsak (Kajohnsak 
) , around the world, is an extremely rare family name. Much more frequently, Kajohnsak is the forename as well as the last name.
Seeta, Thongtra, Thongbai, Tumpiban, Noppakun, Kaewjarus, Kongmanee, Promchuay, Pornbunyanon, Phonlasen, Leangsongchai, Hasitapong, Wongchana, Suwansaard, Kanjanapak, Tanasutinan, Tanasutinun, Thongphikul, Hattayanon, Saithongkum, Chareonsiriwathin, Chaiboonruang, Takanthai, Pankarnjanato, Kanpittaya, Chowkromthong, Chanma, Keadbua, Ratnan, Morakot, Meuanjun, Sooklim, Sritecha, Chaokromthong, Chimjeen, Churwiwat, Wichaiworakul, Katoomkaew, Janpong, Junpong, Jinnawong, Thakham, Toonkitjai, Nanglae, Moolwong, Songsang, Srijitkanda, Chamcheye, Kongtup, and Udomwattanachai