Judge Ian Mulkis granted a divorce decree at a hearing in the Central Family Court in London on Friday.
Neither Mr Redknapp, 44, a former Liverpool and Tottenham midfielder who now works as a television pundit, nor Mrs Redknapp, 43, were in court.
According to court documents, Louise cited ‘unreasonable behaviour’ as the reason for the split.
The judge granted a decree nisi – a marriage formally ends when judges grant decree absolute. A wife or husband can apply for a decree absolute six weeks after a decree nisi is granted.
The Redknapps married in 1998 on a luxury 130ft yacht called Lady Tamara in Bermuda.
Meanwhile just hours before the hearing, Louise was caught on camera performing at the wedding of Strictly choreographer Jason Gilkinson and his partner James.
The former pop star took to the stage on Thursday night and appeared in high spirits as she entertained guests – including Mollie King and Frankie Bridge – with a number of tracks, including her hit 1996 song Naked.
It’s said that the pair are expected to reach amicable terms on custody of their two sons, Charley, 13, and Beau, nine.
The former Eternal singer and Strictly Come Dancing star, 43, confirmed she was living apart from her football pundit husband, 44, in October.
She said at the time she loved her “amazing” partner, with whom she has two children, although she had come to feel like “a sort of Stepford Wife” and she was “coming back to who I really am”.
It has been reported that Louise rediscovered her love of showbiz after her stint on Strictly Come Dancing last year and thanks to a new friendship with fellow contestant Daisy Lowe.
Louise has since been teasing new music and has starred in the West End production of Cabaret.