Breeding males are almost entirely blue with a strong black line from the bill through the eyes and have a long, bright blue tail that is held cocked. 

Females and non-breeding males are predominantly brownish grey with some yellow on their throat and breast. 

Splendid Fairywrens are social birds that form groups of up to 10 individuals which help defend territories against other fairywrens during breeding season when they become more territorial than usual.