Loretto School, in Musselburgh, will launch the app on 21 June. It is designed to make it easy for parents and the rest of the school community to keep up to date with its activities, timetables and news.
The initial launch will give parents the school calendars, a news feed and the ability to view their children's extra-curricular activities.
The second phase, due in September, will show venues of away sports matches, and "real-time" sports match reports.
Loretto's headmaster, Peter Hogan, said: "Schools like Loretto provide a rounded education for their pupils, which gives rise to a full and varied calendar of activities and events each term.
"This can be challenging for parents to keep up with.
"We use the school website and the school's printed calendar, which shows each day of each term in detail, as our main channels for keeping our community informed.
"The addition of the Loretto iPhone app will not only give parents, staff and pupils another option for receiving information from the school but it also allows us to get updated information to our community quickly and efficiently, and we can also use the text alert facility as a more efficient method to target specific parents."