Exhibit 12.1

Domtar Corporation

Computation of ratio of earnings to fixed charges

(In millions of dollars, unless otherwise noted)

	Three months ended
	March 31,		March 31,
	2018		2017
	$		$
Available earnings:
Earnings before income taxes		65		25
Add fixed charges:
Interest expense incurred		16		17
Amortization of debt expense and discount		—		—
Interest portion of rental expense (1)		2		2
Total earnings as defined		83		44
Fixed charges:
Interest expense incurred		16		17
Amortization of debt expense and discount		—		—
Interest portion of rental expense (1)		2		2
Total fixed charges		18		19
Ratio of earnings to fixed charges		4.6		2.3

⁽¹⁾ Interest portion of rental expense is calculated based on the proportion deemed representation of the interest component (i.e 1/3 of rental expense).