During World War II, Clark served with the 9th Queens' Royal Lancers of the British Army in North Africa, Sicily, Italy and Austria.

[4] After six months, Clark was appointed Master of Drawing at the National Gallery of Victoria Art School.

"[3]After finishing his studies at RCA, Clark produced sculptures including Peter Cheyney's hands and a death mask of Evan Walters.

Clark's works in the Australian Federal Parliament House Art Collection include 'Alpha and Omega', 'Ancient Sites' and 'Monument to a Hero II[17][18]'.

Lenton Parr commented,"Marc Clark is widely acknowledged to be a very accomplished and versatile sculptor who has created with equal assurance a succession of commissioned memorial works on a monumental scale and a large number of other sculptures more personally conceived and motivated by his own powers of observation and invention.

The bronze sculpture Stairway to Nowhere (Now in Queensland Art gallery collection) represents his own experience of the result of bombing in WW2 where functional buildings were transformed into symbols of futility.