During a 7-day training and/or competition period, macronutrient intake and distribution was assessed using food diaries, supported by remote food photography and 24-hr multiple pass recalls of youth tennis players categorised by under 12s, under 14s and under 16+ age groups (n = 27). Total energy did not differ between age groups nor type of day (training [TD], competition day [CD]), irrespective of a significant increase in body mass reported in the older players (U16+; p < 0.05). Average intakes were consistently below 2250 kcal·day^-1 (range 1965 ± 317–2232 ± 612 kcal·day^-1). Carbohydrate consumption was below guidelines for all groups (≤6g·kg^-1). Conversely, protein intake met or exceeded guidelines throughout, with intakes ≥2 g·kg^-1 for both the U12 and U14 age groups on both days. Protein intake was ~17% higher on TDs than CDs (p < 0.05), with protein intake at lunch significantly higher on TDs than CDs (p < 0.05). No further differences were observed between breakfast, lunch or dinner between group or day. Inconsistent snacking was reported, with players consuming snacks on less than half of the days reported (46 ± 12% of TDs and 43 ± 30% of CDs). In conclusion, youth tennis players present sub-optimal nutrition practices, appearing to under fuel and under consume carbohydrate for performance, adaptation, recovery and health.