Craig Gordon will sign a new three-and-a-half year contract with Celtic within 48 hours, BBC Scotland understands.
The 34-year-old goalkeeper was the subject of two January bids from English Premier League leaders Chelsea.
Celtic were determined to hold on to the Scotland international and look to have secured his services until 2020.
Gordon, who has made 42 appearances this season, started his career with Hearts and had a spell with Sunderland before joining Celtic in 2014.
Sunderland paid Hearts £9m for Gordon in 2007 but injuries blighted much of his five-year spell with the Black Cats.
He spent two seasons out of the game before Celtic signed him in 2014.
It is believed Chelsea bid around £3.5m for Gordon in January but at the time Celtic boss Brendan Rodgers said: "I have no intention of losing him and we look to arrange a new deal with him."