She studied modern violin with Robert Koff in the USA and Hermann Krebbers in the Netherlands. In 1972 she began to specialize in baroque violin, studying 1972-3 in Amsterdam with Sigiswald Kuijken. Lamon moved to Boston and worked for eight years as a chamber musician and concertmaster for European and US baroque or period instrument orchestras including the Boston Camerata, Banchetto Musicale, the Smithsonian Chamber Players, and the Ensemble for Early Music. Lamon was a founder of Musick for the Generall Peace. In 1974 she won the Erwin Bodky Award for Early Music Performance.

Although she has performed, taught and conducted elsewhere, it is with Tafelmusik that Jeanne Lamon's name has been synonymous for over 30 years. From violin soloist, to concertmaster and music director of the Baroque Orchestra and (later to include the Chamber Choir), she has also been active in planning, marketing, and project development for the ensemble and has been recognized internationally for her achievements.

Lamon appeared as guest soloist with the Tafelmusik Baroque Orchestra 29 March 1979 and again 14 January 1980, when she performed Bach's Violin Concerto in E major. She was appointed concertmaster and music director of Tafelmusik in the fall of 1981, leading most of the orchestra's performances from the concertmaster's chair, as "first among equals." She has been credited as the guiding light behind much of the orchestra's international success.

Lamon first conducted from the traditional podium position in 2001, for the Royal Conservatory of Music (RCM) Orchestra with soprano Isabel Bayrakdarian. She has guest-conducted many Canadian orchestras, including the Calgary Philharmonic Orchestra, the Kitchener-Waterloo Symphony Orchestra, Symphony Nova Scotia, the Vancouver Symphony Orchestra, and the University of Toronto Baroque Orchestra.

She taught in Smith College's Early Music Department (Massachusetts) in the 1970s and, beginning in the 1980s, has taught period violin at the RCM, Wilfrid Laurier University, and the University of Toronto. She has given classes through Tafelmusik initiatives such as the Tafelmusik Baroque Summer Institute.

Lamon may be heard on the Philips, Harmonia Mundi, and other labels, as well as on CDs and DVDs on Tafelmusik Media, the ensemble's own label.

She has received numerous prestigious awards: the Toronto Arts Council's Muriel Sherrin Award (1997); the Joan Chalmers National Award for Artistic Direction (1998); the Canada Council's Molson Prize (1999); the Order of Canada (2001); and the Toronto Musicians' Association Musician of the Year Award (2004).

She wrote the article "Soundoff: En garde, Mr. Zukerman," (Early Music America, summer 2000).

In 2013, Lamon announced that she would be stepping down from her position with Tafelmusik effective in 2014. She has indicated that she expects to remain as music director emerita and maintain her involvement with Tafelmusik's International Baroque Academy.