An Act of Contrition is a prayer for forgiveness recited in repentance during the Sacrament of Reconciliation, or as a private devotional as part of an examination of conscience.

My God, I am sorry for my sins with all my heart.
In choosing to wrong and failing to do good, I have sinned
against you whom I should love above all things.

I firmly intend, with your help,
to do penance,
to sin no more,
and to avoid whatever leads me to sin.

Our Savior Jesus Christ
suffered and died for us.
In his name, my God have mercy.

Amen

Alternate Version

O my God,
I am heartily sorry for having offended You.
I detest all my sins
because I dread the loss of heaven
and the pains of hell.
But most of all because they offend You,
my God,
Who are all good and deserving of all my love.
I firmly resolve with the help of Your grace
to sin no more and to avoid the near occasions of sin.
Amen

Alternate Version

My God,
I am sorry for my sins with all my heart.
In choosing to do wrong
and failing to do good,
I have sinned against You
whom I should love above all things.
I firmly intend, with Your help,
to do penance,
to sin no more,
and to avoid whatever
leads me to sin.
Our Savior Jesus Christ
suffered and died for us.
In His name, my God,
have mercy.
Amen.