Background: Excessive use of specialised formula for cow’s milk allergy was reported in England, but complete analysis has not been undertaken and trends in other countries are unknown. Some specialised formula products, especially amino-acid formula, have high free sugars content. We evaluated specialised formula trends in countries with public databases documenting national prescription rates. Methods: Cross-sectional analysis of national prescription databases in United Kingdom, Norway and Australia. Outcomes were volume and cost of specialised formula, and proportion of infants prescribed specialised formula. Expected volumes assumed 1% cow’s milk allergy incidence and similar formula feeding rates between infants with and without milk allergy. Results: Prescribed volumes of specialised formula for infants rose 2.8-fold in England from 2007-2018, with similar trends in other regions of the United Kingdom. Volumes rose 2.2-fold in Norway from 2009-2020 and 3.2-fold in Australia from 2001-2012. In 2020, total volumes were 9.7 to 12.6-fold greater than expected in England, 8.3 to 15.6-fold greater than expected in Norway and 3.3 to 4.5-fold greater than expected in Australia, where prescribing restrictions were introduced in 2012. In Norway the proportion of infants prescribed specialised formula increased from 2.2% in 2009 to 6.9% in 2020, or 11.2 to 13.3-fold greater than expected. In 2020, specialised formula for infants cost US$117 (103 euro) per birth in England, US$93 (82 euro) in Norway and US$27 (23 euro) in Australia. Soya formula prescriptions exceeded expected volumes 5.5 to 6.4-fold in England in 1994 and subsequently declined, co-incident with public health concerns regarding soya formula safety. In 2020, 30-50% of prescribed specialised formula across the three countries was amino-acid formula. Conclusions: In England, Norway and Australia, specialised formula prescriptions increased in the early 21st century and exceeded expected levels. Unnecessary specialised formula use may make a significant contribution to free sugars consumption in young children.