Institute of Epidemiology & Health Care



We enable research using the Office for National Statistics (ONS) Longitudinal Study - the largest nationally representative longitudinal dataset in the UK

Longitudinal studies follow the lives of individuals over a long period of time, showing us how people are affected by changes in society. The ONS Longitudinal Study contains the census data and some life events data of approximately one million sample members, collected over 40 years. This service is free to the user.

About the ONS Longitudinal Study

About the ONS Longitudinal Study

Find out more about the study

About the ONS Longitudinal Study

Using the ONS Longitudinal Study

Find out how to access and use the data

Data dictionary

Data dictionary

Look up the variables in the study

Celsius Resources


Information and guidance to help you use the data

Research at Celsius


Current and past LS projects and the outputs resulting from this research

About Celsius


Meet the team



SRS and CeLSIUS response to COVID-19

The Office for National Statistics SRS Safe Settings were closed from 5pm 18/03/20, in accordance with government guidelines. They will remain closed until further notice. Emails sent to CeLSIUS staff at their ONS email address will not be answered. We are working from home and have access to our UCL email only.

CeLSIUS access to LS data is also currently suspended, until further notice.

Limited home working will be permitted, in the first instance, where: 
Researchers work for organisations with an Assured Organisational Connectivity agreement in place; AND
The research is important to current operation of the Government and public services. This does not currently apply to LS projects that CeLSIUS supports. Please follow this page for updates.
We are still available, however, to help prepare new project applications and answer any queries about existing projects via celsius@ucl.ac.uk


New CeLSIUS paper

Are ‘healthy cohorts’ real-world relevant? Comparing the National Child Development Study (NCDS) with the ONS Longitudinal Study (LS) (Authors: Gemma Archer, Wei Xun, Rachel Stuchbury, Owen Nicholas & Nicola Shelton) is now out on fast track release  https://doi.org/10.1332/175795920X15786630201754


Guides to using ONS LS data

Guides to ethnicity data, births and fertility data, events data and socio-economic indicators are now available and further guides will be available soon


More news and events