Sutan Sjahrir
Sukarno and Mohammad Roem said that Leimena was an honest politician and a skilled diplomat. Sutan Sjahrir described Leimena's relationship with Sukarno as "telling what he felt sincerely to Sukarno, but he wouldn't leave Sukarno by all by himself". Many of his colleagues saw him as a senior figure, hence his nickname "Om Jo" (i.e. "Uncle Jo"), in contrast to many contemporary figures referred to with the more egalitarian "Bung".