In the above video, Photoshop Principal Product Manager Bryan O’Neil Hughes shares how to remove noise in Photoshop. He highlights the use of the noise removal tools in Camera Raw, as well as hiding other noise by turning down the black levels.
The same controls are also available in Lightroom, so that portion of the tutorial applies to Lightroom as well. Additionally, you can use the image size and Smart Sharpen tools within Photoshop to combat noise.