Around 70 close friends and family were thought to have attended the service at the Hollywood Forever Cemetary.
A spokesperson for the Rolling Stones frontman said: "A small private gathering of family and close friends attended a funeral service for L’Wren Scott today.
“The service with blessings and prayers led by Rev Ed Bacon included memories and words of tribute from Mick Jagger, her brother, Randy Bambrough, Justinian Kfoury, Ira M Hammons-Glass and Adam Glassman.
“Poems were shared by Jagger's daughter, Karis, as well as Ellen Barkin. Mick's daughter, Jade, read Psalm 139, and his grandchildren, Mazie and Zak, read Psalm 23.
“Randy's daughter, Hannah, read Shakespeare Sonnet 18. Will The Circle Be Unbroken was sung by Bernard Fowler with Dave Stewart on guitar.”
L'Wren Scott: Career in pictures
L'Wren Scott: Career in pictures
1/20 L'Wren Scott
L'Wren Scott attends The Serpentine Gallery Summer Party at The Serpentine Gallery in London, 2013
2/20 L'Wren Scott and Val Kilmer
Val Kilmer and L'Wren Scott arrive at a dinner honoring the spirit of Special Olympics at the White House, 2000
3/20 L'Wren Scott and Mick Jagger
L'wren Scott and singer Mick Jagger arrive at the World Premiere of 'Alfie' at the Empire Leicester Square in London, 2004
4/20 L'Wren Scott and Karl Lagerfeld
L'wren Scott and Karl Lagerfeld chat backstage at the Chanel fashion show as part of Paris Fashion Week (Haute Couture) Spring/Summer 2005 in Paris
5/20 L'wren Scott, Victoria Beckham and Amira Casar
L'wren Scott, Victoria Beckham and Amira Casar attend the Chanel fashion show during Paris Fashion Week (Haute Couture) Spring/Summer 2006 in Paris
6/20 L'Wren Scott
Designer L'wren Scott attends the Sidaction Party raising funds in support of AIDS during Paris Fashion Week (Haute Couture) Spring/Summer 2006 at Pavillon D'Armenonville in Paris
7/20 L'Wren Scott
L'Wren Scott arrives at the Nina Ricci show during Paris Spring/Summer 08 fashion week in Paris, 2007
8/20 L'Wren Scott
L'Wren Scott attend the British Fashion Awards 2008 held at The Lawrence Hall in London
9/20 L'Wren Scott
L'Wren Scott arrives at the 'Shine A Light' New York premiere at the Ziegfeld Theater in New York, 2008
10/20 L'Wren Scott and Mick Jager
L'Wren Scott and Mick Jager arrive at the 2009 Vanity Fair Oscar Party at Sunset Tower in West Hollywood
11/20 Dan Williams, Jade Jagger, Mick Jagger and L'Wren Scott
Dan Williams, Jade Jagger, Mick Jagger and L'Wren Scott attend the Jade Jagger shop opening party in London, 2009
12/20 L'Wren Scott and Mick Jagger
L'Wren Scott and Mick Jagger attend the 'Shutter Island' premiere at the Ziegfeld Theatre in New York, 2010
13/20 L'wren Scott and Patti Hansen
L'wren Scott and Patti Hansen attends the 'Stones in Exile' screening at The Museum of Modern Art in New York, 2010
14/20 L'Wren Scott, Oona Ingle-Finch and Sydney Ingle-Finch
L'Wren Scott, Oona Ingle-Finch and Sydney Ingle-Finch attend Finch's Quarterly Cannes Dinner at the Hotel du Cap as part of the 63rd Cannes Film Festival in Antibes, 2010
15/20 Mick Jagger, L'Wren Scott and Tommy Hilfiger
Mick Jagger, L'Wren Scott and Tommy Hilfiger arrive for the screening of 'Stones in Exil' during the 63rd Cannes Film Festival in Cannes, 2010
16/20 Diego Della Valle and L'Wren Scott
President and CEO of Tod's Diego Della Valle and L'Wren Scott attend the 3rd Annual Finch's Quarterly Review Filmmakers Dinner honoring Oscar-winning British film producer Jeremy Thomas and sponsored by Tod's and the IWC at Hotel du Cap-Eden-Roc in Cannes, 2011
17/20 Raf Simons and L'Wren Scott
Raf Simons and L'Wren Scott attend the Christian Dior Haute-Couture Show as part of Paris Fashion Week Fall / Winter 2013 in Paris, 2012
18/20 Stephen Jones and L'Wren Scott
Stephen Jones and L'Wren Scott attend the L'Wren Scott cocktail party during London Fashion Week Fall/Winter 2013/14 in London
19/20 L'Wren Scott
L'Wren Scott attends the British Fashion Awards 2013 drinks reception at the London Coliseum in London
20/20 Jade Jagger, L'Wren Scott, Georgia May Jagger and Mick Jagger
Jade Jagger, L'Wren Scott, Georgia May Jagger and Mick Jagger attend the annual Serpentine Gallery Summer Party co-hosted by L'Wren Scott at The Serpentine Gallery in London, 2013
The Hollywood Forever Cemetery, the resting place of many stars of the silver screen, including Rudolph Valentino and Jayne Mansfield, is one of the oldest in LA.
Security staff at the funeral apparently outnumbered those who turned up to pay their respects.
Standing at the cemetery gates, which were closed to the public and media, they searched vehicles for cameras and recording equipment as they made their way into the grounds.
Jagger had been staying in a Beverly Hills hotel since the Rolling Stones cancelled their tour of Australia.
The fashion designer was found dead by her assistant in her Manhattan apartment on 17 March. A New York Medical Examiner later concluded that she had committed suicide.
Scott launched her high-end fashion label in 2006, which grew to be a favourite among the Hollywood elite. Stars who wore her designs on the red carpet included Nicole Kidman, Sarah Jessica Parker and Michelle Obama.
Following the news of her death, several media outlets speculated that insurmountable debts had but her under huge amounts of stress and emotional strain. They also rumoured that she was set to announce the closure of her line the same week.
In a statement, they said: “Ms. Scott was considering a re-structure of her global business. The L’Wren Scott business consists of a wholesale business of ready-to-wear women’s wear, a bespoke Couture business for private clients, a licensing business, Ms. Scott’s globally recognized work as a Fashion Consultant and stylist and her collaborations such as her recent collection for Banana Republic.
"Her business overall was only seven years old and although some areas of the business had not yet reached their potential other parts of her business were proving successful.
"As a private business, details of income and turnover are not publicly disclosed, however it can be said that the long-term prospects for the business were encouraging. Ms. Scott was very focused on doing what was right for her global business and for the support of her team.
"In terms of figures shown at Companies House in the UK. The parent company of LS Fashion Limited based in America had made a standard loan investment to the UK subsidiary. LS Fashion Limited is fully able to meet the company’s liabilities and pay all suppliers and customers."
Scott also designed stage outfits for Mick Jagger and the Rolling Stones for their Glastonbury and Hyde Park headlining shows last year.
The pair had been together since 2001.