She will appear alongside fellow worship leader Don Moen and classical tenor Andrea Bocelli at the "Voices in Prayer" event held by Catholic charismatic group 'Renewal in the Spirit'.
Thousands are expected to gather in St Peter's Square for the event, which will include prayer for persecuted Christians.
Darlene Zschech, who has written many popular worship songs including "My Jesus, My Saviour (Shout To The Lord)", posted on her Facebook page that she was "honoured" to be asked to sing at the Vatican.
"This is a celebration of unity and peace in the Renewal of the Holy Spirit. Amazing days for the Body of Christ", she wrote.
Speaking before the event, Don Moen said, 'This ecumenical event brings Protestants, Catholics, and Jews together as we pray for our brothers and sisters in Christ who are being martyred and persecuted all over the world today. Although there are many denominational differences throughout the church worldwide, I have seen firsthand how coming together in worship and prayer promotes unity. Join me as we pray for those who are being jailed, beaten, and killed for professing their belief in Jesus Christ."
The news was controversial in some quarters, with one person commenting on Darlene Zschech's facebook page, 'It is always good to take every opportunity to share music with the world that honours God; however I have a hard time to understand how you can be united in seeking the "renewal in the Holy Spirit" with religious leaders who are worshippers of idols and Mary. Unity can happen only when unity is based on the Truth, what the Scriptures says."
This is not the first time Darlene Zschech has worked with the Catholic church. In 2008 she put on a concert as part of World Youth Day. When the Pope Francis' papacy began, the singer tweeted 'God bless Pope Francis...May he lead the Catholic Church into her finest days yet...'