Techniques are provided for sentiment-based adaptations of user representations in virtual environments. One method comprises obtaining information characterizing a first user and a second user interacting with a session of a virtual environment; applying the information to an analytics engine to obtain a sentiment status indicating a sentiment of the second user in the virtual environment, wherein the analytics engine processes the obtained sentiment status of the second user to select an adaptation of a facial expression and/or a body language of a representation of the first user from learned sentiment-based facial expression examples and/or learned sentiment-based body language examples, using the obtained sentiment status of the second user; and automatically initiating a rendering of the virtual environment using the selected adaptation of the facial expression and/or the body language of the representation of the first user in the virtual environment.