We provide the data to analyze the discourse on twitter to COVID19. TweetsCOV19 is a semantically annotated corpus of Tweets about the COVID-19 pandemic. It is extracted based on our long-term Twitter archive TweetsKB and aims at capturing online discourse about various aspects of the pandemic and its societal impact. Metadata information about the tweets as well as extracted entities, sentiments, hashtags, and user mentions are exposed using established vocabularies and W3C standards. The dataset will be continuously updated and currently consists of more than 8 million tweets posted by more than 3 million users and reflects the societal discourse about COVID-19 on Twitter from October 2019 until April 2020.