Poor sleep and late eating are independently associated with adverse metabolic outcomes, yet research has yet to establish whether the macronutrient composition of an evening meal influences sleep and/or next-day metabolism. Therefore, this randomised crossover, open-label study objectively characterised sleep duration and quality after pre-bed ingestion of carbohydrate or protein in 26 young healthy women (n=13) and men (n=13) who were free from sleep disorders. Evening glycaemic responses and next-morning glucose tolerance were also measured to explore associations between pre-sleep nutrient intake, sleep parameters and metabolic responses to each meal. Participants completed three home-based conditions, each separated by a washout interval ≥1-week. During each condition, participants consumed one of three evening ‘snacks’ at 2100 h: (1) WATER (300 mL); (2) CARBOHYDRATE (75 g maltodextrin + 300 mL water); (3) PROTEIN (75g unflavoured whey isolate + 300 mL water). The carbohydrate and protein conditions were matched for total energy content (~300 Kcal). Capillary samples were taken at baseline, 15 min, 30 min and 60 min during the 1-hour postprandial period. Participants were in-bed trying to sleep from 2230-0715 h, with sleep parameters recorded using respiratory polygraphy (SOMNOmedics GmbH, SOMO HD Eco). The next-morning participants completed a 75 g oral glucose tolerance test (OGTT), and capillary glucose concentrations were measured at 0, 15, 30, and 60 min. There were no significant differences across conditions in [median and inter-quartile range] total sleep time (WATER, 489 [474-496] min; CARBOHYDRATE, 479 [466-495] min, and PROTEIN, 482 [451-491] min), sleep efficiency (WATER, 89.9 [87.6-91.8] %; CARBOHYDRATE, 88.4 [85.3-91.1] %; and PROTEIN, 88.1 [84.3-90.9] %), or sleep onset latency (WATER, 3 [1-10] min, CARBOHYDRATE, 6 [1-17] min; and PROTEIN 5 [1-11] min). Pairwise comparisons indicated fewer total wakeups/arousals in the WATER condition (58 [50–65]) compared with the PROTEIN condition (70 [54–94]; P= 0.035). Capillary glucose total AUC for next-morning OGTT differed between conditions (one-way repeated measures ANOVA, p = 0.040), specifically with lower tAUC following the PROTEIN condition (357.5 ± 46.5 mmol·L⁻¹·120 min) compared with CARBOHYDRATE (387.2 ± 52.1 mmol·L⁻¹·120 min; p = 0.005). In summary, acute evening ingestion of carbohydrate or protein following a standardised evening meal did not significantly affect objective measures of sleep in healthy adults without sleep disorders. However, the evening protein condition did result in lower glycaemic responses the following morning.