Greg Avery (born 1963) is a British animal rights activist. He is chiefly known as a founding member of several influential animal rights campaigns — focusing on opposition to the animal testing industry — that have dramatically altered the nature of the animal rights movement in the UK. His latest involvement is with Stop Huntingdon Animal Cruelty (SHAC), an international campaign to force the closure of Huntingdon Life Sciences (HLS), an animal-testing company based in the UK and US. The Guardian describes Avery as the "de facto leader" of SHAC.
Avery is currently serving a nine year jail sentence after his 2008 conviction on charges of conspiracy to blackmail in connection with the SHAC campaign. Avery and six other activists convicted with him, including his second wife Natasha Dellemagne and his first wife Heather Nicholson, are alleged by police to be key figures within the Animal Liberation Front.
Avery was born and raised near Buxton in Derbyshire, one of six brothers. Like his mother, he trained as a tailor. He joined the animal rights movement at the age of 15, and has devoted himself to it full-time ever since.
Avery has been married to Natasha Constance Dellemagne, also an animal rights activist, since 2002. His first wife, Heather Nicholson (formerly Heather James) was active with Avery in founding a number of prominent animal rights campaigns. Avery, Dellemagne (now known as Natasha Avery) and Nicholson remain friends and continue to work together within the movement. In 2004 the three were reported to be living together in a cottage provided by a wealthy supporter, Virginia Jane Steele.
Avery has been a founding member of some of the most prominent and successful animal rights groups and campaigns in the UK. These include the Northern Animal Liberation League, the Consort beagle campaign, Save the Hill Grove Cats, and most recently SHAC. He is also a vocal supporter of the SPEAK campaign, which failed to stop the construction by Oxford University of a new animal testing laboratory on South Parks Road, Oxford.
Avery and Heather Nicholson started SHAC in November 1999 after video footage shot covertly inside HLS by People for the Ethical Treatment of Animals was aired on British television. Footage shot in the UK showed HLS staff shouting at, shaking, punching, and laughing at the animals. Footage shot later in the U.S. appears to show a live monkey being dissected.
Until their 2008 arrests, the "senior members" of SHAC, including Avery, co-ordinated the campaign from a cottage in Little Moorcote, near Hook, Hampshire. Nicholson and the Averys published reports on the SHAC website and by mail, and provided press information and interviews. The website and mailing list serve as a platform for supporters. The senior members would meet every three months to discuss their campaign, compile reports and receive updates from colleagues in the United States and Europe.
Action reports published on the website and mailed out to subscribers would contain details of potential targets and describe protests. According to Greg Avery, "[t]hey've made their beds and now it's time to lie in them, and they're all whining.". Meanwhile, The Times writes, Avery and the core group would privately compile encrypted reports detailing both the legal protests and an "illegal blackmail campaign." The former would be attributed to SHAC, while the latter claimed under the banner of the Animal Liberation Front or Animal Rights Militia. The Guardian writes that the group "targeted thousands of individuals and hundreds of companies in attacks designed to shut down HLS" 
In 1996, Avery spent 18 months on remand after police found incendiary devices in the house where he was staying with another activist. He was later acquitted. He was sentenced in 1998 to six months for affray, and 14 days later that year for offences under the Public Order Act.
In 2002, Avery, Heather Nicholson, and Natasha Dellemagne were jailed for 12 months, six suspended, for conspiracy to incite a public nuisance. In July 2006, Dellemagne and Nicholson were sentenced to 16 months in jail, along with 19-year old Daniel Wadham, who was sentenced to 12 months in detention, for an attack on a car displaying a Countryside Alliance sticker. The three were convicted of verbally abusing and spitting on the occupants, a 75-year-old woman, a woman in her 40s, and a 21-year old man.
On May 1, 2007, after a series of raids involving 700 police officers in England, Amsterdam, and Belgium, 32 people linked to SHAC were arrested, including Avery and Dellemagne, who were charged with conspiracy to blackmail in connection with the SHAC campaign. On July 30, 2008, at Winchester Crown Court, Avery, his wife Natasha Dellemagne, and co-accused Daniel Amos pleaded guilty to conspiracy to blackmail. Avery's first wife, Heather Nicholson, pleaded not guilty but was later convicted of the same crime with three others.
On 21 January 2009 Justice Butterfield ordered Avery to serve nine years imprisonment. Passing sentence the judge told him, "You are not going to prison for your beliefs, you are not going to prison for expressing your beliefs, you are going to prison because each of you has committed a very serious criminal offence."  He was also served with an indefinite ASBO, restricting his future contact with companies targeted in the campaign.