The 11,124 men and 2,150 women were released from various prisons across the country on Friday, after the pardons were issued under a presidential order announced the day before, the state-run New Light of Myanmar daily reported, quoting figures from the Home Ministry.
Under the pardon order, inmates serving sentences of less than 40 years had their sentences slashed by one-fourth, setting free those who have already served their revised terms.
The pardon also commuted death sentences to life imprisonment, and reduced life sentences and jail sentences of more than 40 years to 40 years.
On Dec 30, Thein Sein issued a decree granting amnesty to all the country's political prisoners.
That amnesty set free at least eight political prisoners and dropped charges against several more.