The Supervisory Relationship Questionnaire (SRQ) is one of the few theoretically sound and psychometrically valid questionnaires for measuring the SR within clinical supervision. However, its length can make it difficult to use in clinical practice and research. This study aimed to produce a shorter version of the SRQ (the Short Supervisory Relationship Questionnaire: S‐SRQ) that retained its reliability and psychometric validity. The SRQ's 67 items were initially reduced using the criteria of external, internal and face validity. Two hundred and three UK trainee clinical psychologists then completed a series of online questionnaires including the S‐SRQ and other clinical supervision measures. A Principal Component Analysis identified three components of the S‐SRQ: ‘safe base’, ‘reflective education’ and ‘structure’, and an 18‐item version was produced. Analyses revealed that the S‐SRQ has high internal reliability, adequate test–retest reliability and good convergent, divergent and predictive validity. Participants also rated the S‐SRQ as easy to use and potentially helpful for providing feedback on the SR in supervision. The S‐SRQ (three subscales, 18 items) is a valid and reliable measure of the SR from the supervisee perspective. The current findings also support aspects of existing models of the SR. The S‐SRQ is a promising measure for use in clinical, training and research settings. Copyright © 2014 John Wiley & Sons, Ltd. Key Practitioner Message The Short Supervisory Relationship Questionnaire (S‐SRQ) is a psychometrically reliable and valid 18‐item measure of the supervisory relationship based on the SRQ.Clinically, the measure represents a quick and accessible means for supervisees to assess the quality of their supervisory relationship and discuss this with their supervisors.It can also be used in conjunction with the supervisor‐completed Supervisory Relationship Measure to support a dyadic discussion about clinical supervision and the supervisory relationship.