The past five years have witnessed the beginning of a new era in astrophysics, beginning with the 2015 discovery of gravitational waves from the collision of two black holes. Since then, the Laser Interferometer Gravitational-wave Observatory (LIGO) and its sister project Virgo have observed many more gravitational wave signals from collisions of pairs of black holes. The additional 2017 detection of gravitational waves from the collision of two neutron stars, in coincidence with a gamma ray burst and a kilonova, elevated multi-messenger astrophysics from concept to tool for discovery and exploration. Gravitational waves are a new, important probe for understanding the universe, with a rich science potential ranging from astronomy to cosmology to nuclear physics. This talk will present the latest results from LIGO and Virgo, with their newly expanded gravitational wave catalog, and the outlook for future generations of gravitational-wave detectors.