Millom on Wikipedia.
 

Baptist Church. © James D. Thomas.

A Chapel is shown on the 6" map of 1900 on Newton Street at SD 1768 7992. It post-dates a map of 1867, and is identified here as a Bible Christian Chapel, closing in 1969-70. As of 2022, its site remains un-developed (Streetview).

Holy Trinity. From an old postcard (franked 1914), Bulman Collection. A modern view, and showing the church in the landscape. Both © James D. Thomas. Link.

Millom Methodist Church. The previous church is (2007) being converted to housing to help fund repairs to the current church. Both © James D. Thomas.

Our Lady and St. James (R.C.). © James D. Thomas.

A Primitive Methodist Chapel (called here Holborn Hill P.M. Chapel, and which dates it to 1870 to no later than 1980) in fact stood on Pannet Hill - now Pannatt Hill - at SD 1685 8043. The housing on the site was seen by Streetview in 2022.

St. George. From an old postcard (franked 1914), in Steve Bulman's Collection. A modern view, © James D. Thomas. SD 1716 7999. Link.

Salvation Army. © James D. Thomas.

According to this source, what is identified as a Temperance Hall on a map of 1900, at the junction of Mainsgate Road and St. George's Road, was "by 1920" home to a Welsh Calvinistic Methodist congregation. It's now in secular use, and was seen by Streetview in 2022. SD 1744 7981.