McMullan, who works as a policewoman, will be on the line on Saturday for St Mirren's home fixture against Hearts.
Although this is her first match in the Premiership, she is already highly experienced. She has been a assistant referee in five SPFL Scottish Championship matches this season, including a top-of-the-table clash between Dundee and Falkirk, and in September she was appointed to the League One match between Rangers and Stenhousemuir which had an attendance of nearly 44,000.
McMullan was also involved in the Women's Champions League quarter-final between VfL Wolfsburg and FC Barcelona in March. In 2013, she was an assistant referee at two matches at the FIFA Women's World Cup.
She said: "I was promoted in January, so I've been working hard since then to prepare for this level. When I found out about the appointment yesterday I was absolutely delighted."
"For the match I'll prepare as I would for any other game, but I'll be a bit more nervous! Once the first whistle is blown on Saturday though I'm sure it'll feel like any other game."
Head of Referee Operations John Fleming said: "Kylie's appointment is based on her performance over the past few seasons, and is a justifiable reward having graduated through the same pathway as all male officials.
"Not only has she performed at an exceptionally high level within domestic football, her experience interntaionally in the Women's Champions League and the FIFA Women's World Cup means that she is more than qualified for this Saturday's Premiership appointment.
"Kylie is a role model for all female officials who wish to aspire to officiate the highest level."
The first female assistant referee to be appointed to the English Premier League was Wendy Toms in the 1995-96 season. Sian Massey joined the senior ranks in England three years ago.
In another example of football becoming more equal, French club Clermont Foot yesterday appointed ex-Celtic scout Helena Costa to the role of manager.