Google collected information across almost 100 services, said the Spanish data protection agency, but had not obtained the consent of people to gather information nor done enough to explain what would be done with the data.
The 900,000 euro fine is made up of three separate penalties of 300,000 euros each for breaking different parts of Spanish privacy laws.
Google said it had worked closely with the Spanish data agency during its investigation and said it would await publication of the full report before taking any action.
The search giant could also face further action from other European data protection bodies. In late November, the Netherlands data protection authority said Google’s 2012 policy change also broke its laws. France is also believed to be contemplating levying a fine over Google’s data handling policies.