Alliott Group is an international association of accounting firms and law firms that provide audit, accountancy, tax, corporate finance, commercial law and private client legal services. It ranks as one of more than 200 professional services networks worldwide. The association was established in 1979 and comprises 150 member firms in some 63 countries.
Member firms are independent, mid-market professional practices. At the end of 2015, Alliott Group was ranked by Accountancy Age as the 12th largest international association of accounting firms with aggregated revenues of approximately USD646 million.
Alliott Group is one of 23 members of the European Group of International Accounting Networks & Associations (EGIAN) 
Through its member firms, the association offers services to Small and medium-sized enterprises across a number of sectors and has services groups focused on international tax, global mobility, commercial law and corporate finance/M&A. According to The Daily Telegraph, Alliott Group "is successfully challenging large international firms in offering clients a global solution to their accounting, legal and consultancy needs." 
|Alliott Peirson International (1979–1999)|
|Private limited company|
|Headquarters||Worldwide, with Executive Office in Petersfield, UK, London|
|Worldwide, 200+ cities|
Colin Farmer(Worldwide Chair)|
James Hickey (CEO)
Jamie Towers(Deputy Worldwide Chair)
The original founding firms already had working relationships and mutual clients but established a formal association in Alliott Peirson International, Alliott Group’s forerunner, in 1979. The association’s aim was to meet the needs more efficiently of those clients that needed assistance when expanding into or facing challenges in different jurisdictions around the world. As client demand for services in new locations grew, member firms were (and continue to be) appointed in key commercial cities across the world.
According to Inside Public Accounting, "Alliott Group was one of the first international groups to adopt an interdisciplinary approach."  The association opened its membership to law firms in 2004, and as of June 2017, 31 law firms are members. As a result, Alliott Group may be listed as an international law firm network  or as one of a small number of Multidisciplinary professional services networks.
2009: John Jones (Santa Rosa, CA, USA) 
2012: John Kleopas (Athens, Greece) 
2016: Kenneth J. Miles (Los Angeles, CA, USA) 
2017: Colin Farmer (London, UK) 
1979: Alliott Peirson International formed.
2015: Alliott Group wins 2015 Accountancy & Law Alliance of the Year in the Global Market award.
2016: Alliott Group won the 2016 Rising Star International Association of Accounting Firms award.
2016: Expansion of alliance membership to Australia (Melbourne), Japan (Tokyo), Netherlands (Eindhoven), Northern Ireland, Saudi Arabia and South Africa (Johannesburg and Cape Town)
2017: Expansion of alliance membership to Spain (Madrid)
2018: Expansion of alliance membership to Canada (Toronto), Oman, Tunisia and Zambia.
1979: London, UK
1980: London, UK
1981: Copenhagen, Denmark
1987: Edinburgh, Scotland
1988: Surfers Paradise, Australia
1989: Vienna, Austria
1991: Orlando, FL, USA
1992: Barcelona, Spain
1993: Hong Kong
1994: Melbourne, Australia
1995: Montreal, Canada
1996: Penang, Malaysia
1997: Abu Dhabi, UAE
1998: San Diego, CA, USA
1999: Melbourne, Australia
2001: Event cancelled
2002: Mexico City
2003: Miami, FL, USA
2004: Cairns, Australia
2005: Cape Town, South Africa
2006: Beijing, China
2007: San Francisco, CA, USA
2008: Athens, Greece
2009: Boston, MA, USA
2011: Barcelona, Spain
2012: San Diego, CA, USA
2013: Hong Kong
2014: Johannesburg, South Africa
2015: New York, NY, USA
2016: London, UK
2017: Sydney, Australia
2018: Vancouver, Canada
2019: Madrid, Spain