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 (LS) contains the census data and some life events data of approximately one million sample members, collected over 40 years. CeLSIUS is funded by the ESRC to provide free support to researchers wishing to use this data.

About the ONS Longitudinal Study

About the ONS LS

Find out more about the study

About the ONS Longitudinal Study

Using the ONS LS

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 ONS LS research projects and the resulting outputs

About Celsius


Meet the team

Wordpress dashboard

Linking our Lives Blog

Our blog showcases outstanding research using the ONS LS


Linking our Lives Podcast

In conversation with researchers and users of ONS LS research


Research and policy briefs

Policy and research briefing notes on research using the ONS LS

News and events


Webinar: Getting your ONS LS outputs cleared: A guide to completing the form, Monday 19th February 2024, 2-2.50 pm

Researchers using the ONS LS must get their pre-publication and publication research outputs approved, by submitting them along with Request for SRS: Output from ONS LS Project form (Word). This webinar will guide you, step-by-step, through the completion of this form and we will answer any questions you may have regarding the outputs approval process. Register with Eventbrite to secure your place.


Webinar: Applying to use the ONS Longitudinal Study: A guide to completing the forms

This event took place on 22nd January 2024; the presentations and recording of the webinar are now available through our Resources page.


UKLS' Annual Conference, 16 - 17 April 2024 at Queen's University, Belfast

The above conference will be hosted by NILS-RSU in Belfast, co-hosted by SLS-DSU & CeLSIUS. The programme will include sessions on the impending Census 2021 linkage, an expert panel on the future of longitudinal studies and population statistics and a choice of interactive workshops. Information on the provisional programme and abstract submission for posters is available via the following links:



Information on travel and accommodation is available here.


Timescales of availability of 2021 LS data

ONS has provided the following update:  

Beta testing of the 2021 LS data will not start before March 2024 and the 2021 LS research database is therefore not likely to be available before the latter half of 2024. 

Please contact celsius@ucl.ac.uk if you have any queries about this.


More news and events



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