St Katherine's Church, Lincoln also known as "Southside" and "St Katherines Cathedral Church" is a Grade II-listed church in Lincoln, Lincolnshire, England. It is a former Methodist church in the Boultham and St Catherine's areas of the city. It was first opened in 1887 with the tower and spire being added later. During its use as a place of worship, it was dubbed "Lincoln's second cathedral.

Lincoln is a cathedral city and district in Lincolnshire, England, of which it is the county town. In the 2021 Census, the Lincoln district had a population of 103,813. The 2021 census gave the urban area of Lincoln, including North Hykeham and Waddington, a recorded population of 127,540.