The German firm will supply 13 SWT-3.4-108 turbines on 79.5-metre high towers to the Zadar VI extension project in the Lika region.
Delivery is expected in the first half of 2017, with project completion in the summer. Siemens will service the turbines for 14 years following installation.
Siemens said it has installed approximately 40 turbines in Croatia, totaling around 100MW.
Overall, by end of September 2016, Croatia had 415MW of online capacity, adding just 34MW this year, according to Windpower Intelligence, the research and data division of Windpower Monthly.