Melissa Natalie Tkautz (born 24 January 1974) is an Australian actress, singer, model, and presenter. She played the role of Nikki Spencer on the popular Australian TV soap opera E Street, from September 1990 to May 1993. During the early 1990s she had a solo music career, performing mononymously as Melissa, and had top 20 hits on the ARIA Singles Chart with "Read My Lips" (Number One, June 1991), "Sexy (Is the Word)" (No. 3, September) and "Skin to Skin" (No. 16, April 1992). "Read My Lips" also became a Number One hit in Sweden. Her debut album, Fresh, was released in June 1992 and peaked at No. 15 on the ARIA Albums Chart.

After her stint on E Street, Tkautz has appeared on Paradise Beach (1993–94), Pacific Drive (1996–98), All Saints (2001–02, 2004), Swift and Shift Couriers (2008, 2011) and Housos (2011). Her modelling career has included early child modelling, then as a teen in various pop entertainment magazines and from 1996 on fashion and men's magazines. On 4 December 2005, she issued her second solo album, Lost & Found, which provide a single, her cover version of "The Glamorous Life", which appeared in the top 40. In August 2011 she issued a compilation album, The Hits & More. In February 2009 Tkautz married a finance businessman, Kwesi Nicholas, her partner of five years; outside her performance career she uses her married name, Melissa Nicholas.