The four founding partners all met at Wolff Olins: Gerry Barney, David Bristow, Kit Cooper, Terence Griffin and set up the company in 1978. All but Barney retired from the business in 1996 after Mick Nash took over as managing director. The company operated an office in Berlin from 1987 to 2004.
The agency originally started as a graphic design agency yet evolved and increased its disciplines as client demands grew. This has been central to the agency's growth and it now covers typography, architecture, interior design, corporate branding, packaging, 3D Graphics and online design.
The agency took its name from the address of its original offices situated on Sedley Place adjacent to Oxford Street and Woodstock Street in London. This street was after Orlando Sedley an 18th Century Furniture maker who had his workshops located there. The agency relocated to its current offices in 1985 on Venn St, Clapham.
- The Coca-Cola Piccadilly Circus Sign as it appears today was designed and project managed by Sedley Placed in 2003, originally the world's widest curved LED screen. They are now the retained by Coca-Cola produce all content for the sign. Sedley Place also designed the very first LED sign at Piccadilly Circus for Coca-Cola replacing their previous neon sign.
- Sedley Place has worked with Diageo for over twenty years developing brands including Johnnie Walker (Blue, Gold, Green and Black labels), Cardhu, Talisker, Tanqueray 
- VAG Rounded Typeface was created by Gerry Barney as part of a rebranding project for VW dealerships. This font, now in the public domain is widely used and features on all Apple laptop and computer keyboards.
- From a simple verbal brief to create a spinning bottle for the Asian market the unique Revolve Bottle  was created for Chivas Brothers
- Working with Michael Wolff (of Wolff Olins) Gerry Barney penned the now well known Hed Kandi record label logo 
Sedley Place has employed a number of notable British designers:
- "Jock Kinneir + Margaret Calvert / Designing Modern Britain - Design Museum : - Design/Designer Information". Design Museum. Retrieved 2009-10-13.
- Whitehead, Jennifer (2003-10-01). "Coca-Cola unveils intelligent billboard at Piccadilly Circus - advertising news - Campaign". Campaignlive.co.uk. Retrieved 2009-10-13.
- "Sedley Place livery for Cardhu | News". Design Week. 2003-12-11. Retrieved 2009-10-13.
- "Spirits News". The Drinks Report. Retrieved 2009-10-13.
- "Typographic Abbreviations Series #2: VAG « MyFonts Musings". Myfonts.wordpress.com. 2006-11-17. Retrieved 2009-10-13.
- "VAG Rounded". Typedia. Retrieved 2009-10-13.
- 50 trade secrets of great design ... - Google Books. Books.google.co.uk. Retrieved 2009-10-13.
- "Unreal Press: Hed Kandi To Stretch Its Legs After Rebrand". Unreal-uk.com. 2006-08-31. Retrieved 2009-10-13.
- "the johnson banks thought for the week". Johnsonbanks.co.uk. Retrieved 2009-10-13.
- "2006 AGM". ATypI. Retrieved 2009-10-13.
- "Lambie-Nairn". Lambie-Nairn. Retrieved 2009-10-13.
- Paul Mcpherson Design. "About". Paul McPherson Design. Retrieved 2009-10-13.