This guidance is for people who may be considering including measures of loneliness on their surveys. It will be useful to those in central or local government considering how best to measure loneliness in keeping with the Government’s Loneliness Strategy announced in October 2018. It will also be helpful to those working in academia or in the private sector who would like to measure loneliness as part of their work. Using the approach recommended here will help to align your survey with this wider initiative and, in doing so, make a more positive contribution to the evidence base on loneliness.