Originally a suicide attack database (1974-), now research covers areas including international politics, security, and trade

Annual report from the respected Simon Wiesenthal Center that analyses websites & social media platforms for online hate by neo-Nazis & other extremists, including government involvement

Constructed by Sara Polo in the Government Department, this dataset covers 1970-2009 and draws upon the existing Global Terrorism Database and Ethnic Power Relations database to compile data on ethnic terrorism

Think tank allied to the Global Counterterrorism Forum and based in UAE. Aims to prevent and counter extremism through evidence-based research & programs

Data sheet of major incidents 1989-

Role is to inform the public and others of UK terrorism legislation

ICCT is a think tank based in The Hague, Netherlands. It provides research, policy advice and training to support better counter-terrorism policies and practices worldwide

Significant collection of documents left behind by Islamic State following the capture of Mosul, Iraq, in 2016. The documents have been digitised & made available by George Washington University's program on Extremism, and the majority translated from Arabic into English

The ITERATE project is an attempt to quantify data on the characteristics of transnational terrorist groups, their activities which have international impact, and the environment in which they operate.
Library provides access to: Hostage File: 1978-2005. ITERATE Common File: 1968-2016. ITERATE Codebook 2016

Stanford University project mapping militancy over time & space. Contains detailed profiles of terrorist groups (see also US State Dept. reports)

Part of the START Terrorism Data Archive, hosted on Harvard Dataverse. MAROB covers 16 countries in the Middle East and North Africa over the period 1980-2004. It provides information on the characteristics of 22 ethnopolitical organizations most likely to employ violence and terrorism in pursuit of perceived grievances.

Well known database, freely accessible, of terrorist incidents recorded between 1968 and 2009.

From well-known Norwegian centre C-REX, RTV documents right-wing terrorism and violence in Western Europe since 1990. Each event has been coded on a range of variables, including time and location, perpetrator and victim characteristics, organizational affiliations, weapon types, and number of casualties. The dataset includes only the most severe types of events

Comprehensive website on terrorism & low intensity warfare in the region (particularly India), offering publications & data

Centre associated with the US Department of Homeland Security. Useful free access databases including:
Global Terrorism Database which provides information on terrorist attacks, bombings and incidents worldwide from 1970- onwards. The GTD incorporates the Worldwide Incidents Tracking System (2004-2012), which was maintained by the National Counterterrorism Center until 2012.
BAAD Database (Big, Allied & Dangerous) about terrorist groups around the world
PIRUS (Profiles of Individual Radicalization in the US) which contains individual-level information on the backgrounds, attributes, and radicalization processes of over 2,100 extremists who adhere to far right, far left, Islamist, or single issue ideologies in the United States (1948-)
Terrorism & Extremist Violence in the US (TEVUS) 1970- which is compiled using data from 4 datasets (American Terrorism Study, GTD, Profiles of Perpetrators of Terrorism in the US (PPT-US), and US Extremist Crime Database (ECDB))

Tech Against Terrorism is an initiative launched and supported by the United Nations Counter Terrorism Executive Directorate (UN CTED) working with the global tech industry to tackle terrorist use of the internet whilst respecting human rights. Useful reports available on the website

Country reports on terrorism 2004-

Dataset compiled by Brian Phillips (University of Essex) and colleagues, to examine militant group competition in Africa & Asia 1990-2015. Accompanies the article: https://doi.org/10.1177/00220027231208708