This thesis concerns the use of data from the Gaia satellite to study Galactic planetary nebulae. Gaia is a recent ESA mission measuring positions, parallaxes, proper motions, and photometry of nearly two billion stars in the Milky Way. Several thousand of these stars are passing through the planetary nebula phase, an important phase that low and intermediate mass stars experience towards the ends of their lives before becoming white dwarfs. The thesis has three main contributions. The first is the development and application of an automated technique for identifying the central stars of planetary nebulae in the Gaia catalogue. The second is a statistical method for identifying photometric variability in these central stars. Periodic photometric variability is often an indicator of binarity, which is now known to be key to the formation and shaping of a significant fraction of planetary nebulae. The method is validated through ground-based follow up observations. Finally, more precise distances from Gaia parallaxes are combined with newly obtained ground-based narrowband imagery to determine and investigate the planetary nebula luminosity function of the local Milky Way. Besides being an important extragalactic indicator, this distribution of nebula magnitudes is related to the evolution of planetary nebula central stars across different masses. Distances and photometry from Gaia allow the brightness of the nebula and the evolution of the central star to be related directly in unprecedented detail.