Lillicrap was born in Brisbane. He played prop and was capped seven times for Australia between 1985 and 1991. He was part of the 1984 Wallabies Grand Slam Tour squad and played for Australia at two Rugby World Cups – the inaugural tournament in 1987 and as part of the victorious Wallabies squad in 1991. In 1999 he was named in the Queensland Team of the Century. He represented Queensland from 1984 to 1994.
