The incident is said to have occurred at 11:30 local time (17:30 GMT).
The mass shooting happened during the Sunday Service at the First Baptist Church in Sutherland Springs in Wilson County.
According to the BBC, the police commissioner at the scene confirmed that at least 27 people had died, while several others are reported to be injured.
Local FBI agents were sent to the situation, and the gunman is reported to have been killed in the aftermath of the initial shooting.
The area has now been cordoned off and further investigations are taking place.
Several Casualties Reported in Texas Church Shooting – https://t.co/Mo9IE0qkb2 pic.twitter.com/trBg5bGSBJ
— 1 News Net (@1_newsnet) November 5, 2017