Ignacio Gregorio Comonfort de los Ríos (12 March 1812 – 13 November 1863) is a Mexican politician and soldier.

He becomes President of Mexico in 1855 after a revolt based in Ayutla overthrows Santa Anna.

Comonfort is a moderate liberal who tries to maintain an uncertain coalition, but the moderate liberals and the radical liberals are unable to resolve their sharp differences.

During his presidency, the Constitution of 1857 is drafted, creating the Second Federal Republic of Mexico.

The new constitution restricts some of the Catholic Church's traditional privileges regarding land holdings, revenues and control over education.

It grants religious freedom, stating only that the Catholic Church is the favored faith.

The anti-clerical radicals score a major victory with the ratification of the constitution, because it weakens the Church and enfranchises illiterate commoners.

The constitution is unacceptable to the clergy and the conservatives, and they plot a revolt.

With the "Plan of Tacubaya" in December 1857, Comonfort tries to regain the popular support from the growing conservative pro-clerical movement.

The liberals fail, however, as conservative General Félix Zuloaga overthrows Comonfort in January, 1858.