In a five-minute session, the court confirmed the death sentence against Yehya Dalimi and a 10-year prison term for Mohammad Moftah.
The two defendants failed to appeal the rulings, commenting that the trial was politically motivated and directed against freedom and the partisans of liberties.
They stressed their rejection of violence and terrorism and refusal of sectarian war, accusing the authorities of having tried them on a sectarian basis.
Al-Houthy and his followers belong to the Zaydi sect, an offshoot of the Shiite confession, and waged a rebellion in north Yemen last year to press for more political rights.
The courtroom closed its doors Saturday to the public, but scores of men and women demonstrated outside the tribunal building carrying placards demanding an independent and just judicial process.
The two defendants were convicted of organizing armed gangs, backing al-Houthy's rebellion, conspiring against the regime, and collaborating with Iran through illegitimate channels with the aim of "undermining state security and inciting sectarian strife."