This lecture will review the latest paleomagnetic and environmental magnetic lessons gathered from speleothems, including stalagmites and flowstones. No matter how quiet and pristine a cave setting may appear, all speleothems contain assemblages of magnetic minerals. In most settings these iron oxide minerals are derived largely from overlying soils, though minor fractions may also come from the residuum of dissolved bedrock, reworked sediment carried by episodic floods, geomicrobiological activity, and even windblown dust. Regardless of their origin, these minerals become aligned with Earth’s ambient magnetic field before they are fixed within a speleothem’s growing carbonate matrix. Modern paleomagnetic studies are using ever-smaller speleothem samples, which has allowed researchers to study the finer details of important forms of short-term geomagnetic behavior, ranging from excursions to temporal oscillations of the South Atlantic magnetic anomaly. It has also enabled some researchers to document systematic remanence anisotropy along the steeply dipping flanks of stalagmites, a phenomenon that appears to be controlled by speleothems’ carbonate fabrics. While collecting samples along the growth axis of a stalagmite is a good strategy to minimize such remanence bias, there are more robust, multi-sample methods to correct for this effect, which will become increasingly important as speleothem-based paleomagnetic studies are incorporated into global and regional geomagnetic field models. Environmental magnetic studies from speleothem continue to provide critical information about the hydrogeology and soil development immediately above cavern systems. By integrating information about the composition, concentration, and grain size distribution of magnetic minerals with trace element and isotopic geochemistry data from speleothems, rock magnetists can play pivotal roles in studies of paleoclimate, anthropological activities, wildfires, and much, much more.