The veteran broadcaster, known for his velvety voice on radio and television, died of cancer on January 31 aged 77.
Limerick-born Wogan, one of Britain and Ireland’s most famous stars, was hailed as a “national treasure” following his death.
The BBC press office tweeted: “A Service of Thanksgiving for Sir Terry Wogan will take place at Westminster Abbey on 27 September. Further details in due course.”
Leading figures in showbusiness and politics have paid tribute to the much-loved personality, with British prime minister David Cameron saying he was “someone millions came to feel was their own special friend”.
He was last on air on BBC Radio 2 on November 8, and days later was forced to pull out of presenting Children In Need at the last minute due to health issues.
Wogan has already been remembered in a special episode of Songs Of Praise.
He had spoken in recent years about not believing in God after the death of his three-week-old daughter Vanessa in 1966.
Meanwhile, a Eurovision boss has said that Wogan “totally spoiled Eurovision” by mocking the acts during his acerbic commentary.
Wogan was accused of creating a generation who see the show as irrelevant and “kitsch” by Christer Bjorkman, the Swedish producer of this year’s contest, who said he would “never” have given him the job.
The Scandinavian country is known for its earnest Eurovision entries and has won six times with contributions that went on to become smash hits, from ‘Waterloo’ by Abba in 1974 to ‘Euphoria’ by Loreen in 2012.
Wogan first fronted the BBC’s Eurovision coverage in 1971, and his stinging commentary proved to be one of the many highlights of his career.