Lines of the faithful began streaming into a soccer stadium in Guadalajara to watch the ceremony, hours before it began.
They filled nearly all of the 60,000 seats at the arena, where Cardinal Jose Saraiva Martins, prefect of the Congregation for Saints, arrived from Rome to oversee the ceremony.
Those without tickets ringed the stadium and listened outside, while thousands of others tuned in to radio and television broadcasts in nearby restaurants and shops.
The Portuguese-born Mr Saraiva Martins, who heads the Vatican office overseeing sainthood, called the martyrs "faithful witnesses" to the power of the church and promised that history has not forgotten them.
Beatification is the last formal step before sainthood.
The Ceremony
Massive, glossy sketches of the martyrs adorned the soccer field, arranged around a towering cross.
Pope Benedict XVI appeared on video screens, reading a message from the Vatican.
"They are a permanent example for us, an encouragement to give concrete testimony of our own faith in today's society," the Pope said in Spanish.
The martyrs died during the 1926-29 Cristero War, that saw tens of thousands perished fighting the government over religious restrictions such as the banning of public masses and religious garb.
The conflict was sparked by the 1917 constitution that grew out of the Mexican Revolution and tightened already tough limits, capping a century of setbacks for the Catholic Church.
The church had enjoyed a government-imposed monopoly of faith for most of the 300 years following Spain's conquest of Mexico in 1521.
Pope Benedict XVI’s first beatified Mexicans
The ceremony marked the first Mexican beatifications since April
2004, when Pope John Paul II beatified Guadalupe Garcia.
Guadalupe a Guadalajara native founded hospitals and a religious order that has 22 foundations in Mexico, Peru, Iceland, Greece and Italy.
In 2000, John Paul II canonised 25 Mexican martyrs from the era of the Cristero uprising.
The best-known of that group was Father Cristobal Magallanes, who reputedly pardoned his killers as he died by firing squad May 25, 1927.