Mark Gordon Ella, AM (born 5 June 1959) is an indigenous Australian former rugby union footballer. Ella played at flyhalf/five-eighth and was capped by the Wallabies 25 times, captaining Australia on 10 occasions.

Ella made his debut tour with the Wallabies on the 1979 Australia rugby union tour of Argentina. He would later make his Test debut for Australia during the 1980 Bledisloe Cup Test series, in which the Wallabies defeated the All Blacks two games to one – the first three-Test series victory Australia against New Zealand since 1949, the first series victory over the All Blacks on Australian soil since 1934, and the first occasion the Wallabies successfully retained the Bledisloe Cup. In 1982, Ella was made captain of the Australia national rugby union team and he would go on to captain the Wallabies on 10 occasions from 1982 to 1983. After Arthur Beetson, he was the second indigenous Australian to captain a national sports team. Ella captained a depleted Australian team on the 1982 Australia rugby union tour of New Zealand, which the Wallabies would lose one game to two against the All Blacks. However, Australia scored 316 points in 14 matches on tour, including 47 tries. Ella is perhaps most famous for his performances on the 1984 Australia rugby union tour of Britain and Ireland, during which Australia achieved rugby union's Grand Slam by defeating the Home Nations in four consecutive Tests, with Ella scoring one try in each Test.

He and his brothers Glen (his twin) and Gary were educated at Matraville High School, where they learned to play rugby. All three went on to play for the Australia national team. Mark also played for Randwick and New South Wales domestically. ^{[citation needed]}

Bob Dwyer, former coach of the Wallabies, in his first autobiography The Winning Way, claimed Ella to be one of the five most accomplished Australian players he had ever seen. Dwyer hailed Ella as number one "for mastery of the game's structure". This is perhaps due to Dwyer's perspective on the five-eighth's role: "A five-eighth's primary function is to draw defence and so open up space for the runners outside him." This conveys how Ella approached playing the five-eighth position.

Ella's approach to playing the five-eighth position was unique and different from that of any other five-eighth of his era, and involved many obvious characteristics different from those of his five-eighth contemporaries. Gareth Edwards writes in 100 Great Rugby Players that: "Firstly, he stands closer to his scrum-half than most other stand-off halves I have played with or against, so that he pulls back row forwards on him at an angle which makes it hard for them to change direction, once he has released possession, to harass the midfield". Ella describes the distance from which he stood from the scrum-half in his book Running Rugby, "Generally, I stood about 5 metres from the halfback and about 4 metres behind him. According to the old formula for the right-angled triangle, this means I was no more than 3 metres wide of him".

Relatively straight running was a distinguishable trait associated with Ella's game. This was intended to draw defenders towards him at a certain angle and help unleash his teammates into gaps. Ella wrote:

Standing flat demands exceptional ball handling skills, which were a hallmark of Ella's game. Ella's dependable hands were lauded by former Scottish rugby international Norman Mair in The Scotsman: "Ella has hands so adhesive that when he fumbled a ball against Scotland (in 1984) you would not have been surprised to see those Australians of the appropriate religious persuasion cross themselves."

Concerning the manner in which Ella regularly received the ball from his scrum-half; Ella gave no quarter to the speed at which the ball was delivered to him, regardless of how close he stood, trusting in his ability to safely hold the ball. Ella writes: "Once you have positioned yourself, the next thing is to demand a fast pass from the halfback. The quicker the ball reaches you the better, for every fraction of a second is important to the five-eighth, given that the opposition can be on top of him in less than two seconds. I used to insist on having the ball passed to me like a rocket."