Easter 2017 is celebrated Sunday April 16th, following the holy week that starts on 10th of April 2017 (Holy Monday).
For 2017 Catholic Easter and orthodox Easter falls on the same date for the first time since 2014. This not common as the dates of the Catholic easter are calculated using the Gregorian Calendar, unlike Orthodox Easter which dates are calculated using the Julian Calendar.
Orthodox Easter 2017 is celebrated on the same date with Catholic easter 2017, on Sunday April 16th, following the holy week that starts on 10th of April 2017 (Holy Monday).
The date of the Orthodox Easter Sunday is the Sunday following the Paschal Full Moon (PFM) date for the year, using the Julian Calendar. For 2017 the date of the Orthodox Easter is April 16th. Catholic Easter on the other hand is calculated based on the Gregorian calendar, and it relatively rare to fall on the same date. The next year that this will happen will be 2025!