In the five years prior to Oh Little Fire, Harmer was involved with environmental activism and made guest appearances on albums of Bruce Cockburn, Neko Case, Blue Rodeo, The Weakerthans, and Great Big Sea.

Music critic James Christopher, writing for Allmusic wrote: "Harmer's winning blend of country, folk, and indie pop is propelled, in part, by her even, expressive tenor...

"[1] Michael Joyce of The Washington Post praised the album, writing "...she's still capable of coming up with poetic musings perfectly suited to her wistful soprano, as the minor-key ballad "New Loneliness" illustrates.

"[7] musicOMH gave the albums 4 of 5 stars and wrote "Oh Little Fire is a perfectly packaged container for pop gems, and Harmer falls right in place in the midst of such a sugar-sweet and swooning backdrop.

and noted that "one of the prevailing characteristics of these eleven songs is that they mostly lack a distinctive style, erring instead toward the kind of spiceless pleasantness that would make Harmer’s music easy to slip into pop-country radio rotation.