Thomas married Margaret Tydfil Price between 1 Jul 1912 and 30 Sep 1912 in Pontypridd District, Glamorgan, Wales. Margaret was born on 17 Aug 1889 in Pontypridd District, Glamorgan, Wales; died between 1 Jul and 30 Sep 1970 in Cardiff District, Glamorgan, Wales. [Group Sheet]

1. Francis Glyndwr Downing was born on 6 Oct 1913 in Pontypridd District, Glamorgan, Wales; died in Feb 1996 in South Glamorgan District, Glamorgan, Wales.
2. Emrys Kenneth Downing was born on 15 Sep 1915 in Pontypridd District, Glamorgan, Wales; died on 15 Mar 1992 in Cardiff, Glamorgan, Wales.
3. Idris Thomas Downing was born on 28 Jan 1918 in Pontypridd District, Glamorgan, Wales; died on 15 Jan 1991 in Cardiff, Glamorgan, Wales.
4. Richard Vaynor Downing was born between 1 Jan & 31 Mar 1920 in Pontypridd District, Glamorgan, Wales; died on 10 Feb 1942 in Singapore; was buried in Singapore Memorial< Kranji, Singapore.