Dominion Diamond Corporation

Canada’s Largest Independent Diamond Producer and Third Largest Producer Globally by Value

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Fiscal Year 2015 Fourth Quarter & Year End Results

TSX/NYSE: DDC

Forward Looking Information

Caution Regarding Forward Looking InformationCertain information included in this presentation constitutes forward-looking information within the meaning of Canadian and United States securities laws. Forward-lookinginformation relates to management’s future outlook and anticipated events or results, and can include statements or information regarding plans for mining, development,production and exploration activities at the Company’s mineral properties, sales estimates, expected sales, and expected operating costs. Forward-looking informationincluded in this presentation includes the estimated mine life and other plans, timelines and targets for mining, development, permitting, production and exploration activities atthe Ekati Diamond Mine and Diavik Diamond Mine, estimated reserves and resources at the Ekati Diamond Mine and Diavik Diamond Mine, production, capital and operatingcost estimates for the Ekati Diamond Mine and the Diavik Diamond Mine and the Company’s intention to pay a regular dividend on its common shares.

Forward-looking information is based on certain factors and assumptions, including, among other things, the current mine plans for each of the Diavik Diamond Mine and theEkati Diamond Mine; construction and exploration activities at the Company’s mineral properties; the timely receipt of required regulatory approvals; mining methods; currencyexchange rates; estimates related to the capital expenditures required to bring the Jay pipe and A-21 pipe into production; required operating and capital costs; labour andfuel costs; world and US economic conditions; future diamond prices; and the level of worldwide diamond production. While the Company considers these assumptions to bereasonable based on the information currently available to it, they may prove to be incorrect. Forward-looking information is subject to certain factors, including risks anduncertainties, which could cause actual results to differ materially from what the Company currently expects. These factors include, among other things, the uncertain natureof mining activities, including risks associated with underground construction and mining operations, risks associated with joint venture operations, including risks associatedwith the inability to control the timing and scope of future capital expenditures, risks associated with the estimates related to the capital expenditures required to bring the Jaypipe and A-21 pipe into production, the risk that the operator of the Diavik Diamond Mine may make changes to the mine plan and other risks arising because of the nature ofjoint venture activities, risks associated with the remote location of and harsh climate at the Company’s mineral property sites, variations in mineral reserve and mineralresource estimates, grade estimates and expected recovery rates, failure of plant, equipment or processes to operate as anticipated, risks resulting from the Eurozonefinancial crisis, risks associated with regulatory requirements and any delays in receiving required regulatory approvals, the risk that diamond price assumptions may prove tobe incorrect, the risk of fluctuations in diamond prices and changes in US and world economic conditions, uncertainty as to whether dividends will be declared by theCompany’s board of directors or the Company’s dividend policy will be maintained, or the Company’s the risk of fluctuations in the Canadian/US dollar exchange rate andcash flow and liquidity risks. Please see the Company’s most recently filed Management’s Discussion and Analysis, as well as the Company’s current Annual InformationForm, both available at www.sedar.com and www.sec.gov, respectively, for a discussion of these and other risks and uncertainties involved in the Company’s operations.Actual results may vary from the forward-looking information.

Readers are cautioned not to place undue importance on forward-looking information, which speaks only as of the date of this presentation, and should not rely upon thisinformation as of any other date. Due to assumptions, risks and uncertainties, including the assumptions, risks and uncertainties identified above, actual events may differmaterially from current expectations. While the Company may elect to, it is under no obligation and does not undertake to update or revise any forward-looking information,whether as a result of new information, future events or otherwise at any particular time, except as required by law.

Technical InformationThe scientific and technical information relating to the Ekati Diamond Mine included herein has been prepared and verified by Dominion, operator of the Ekati Diamond Mine, under the supervision of Peter Ravenscroft, FAusIMM, of Burgundy Mining Advisors Ltd., an independent mining consultant, and a Qualified Person within the meaning of National Instrument 43-101 of the Canadian Securities Administrators and is given as of January 31, 2015.

The scientific and technical information relating to the Diavik Diamond Mine included herein has been prepared and verified by Diavik Diamond Mines (2012) Inc., operator ofthe Diavik Diamond Mine, under the supervision of Calvin Yip, P. Eng., Principal Advisor, Strategic Planning of Diavik Diamond Mines (2012) Inc., and a Qualified Personwithin the meaning of National Instrument 43-101 of the Canadian Securities Administrators, and is given as of December 31, 2014.

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TSX/NYSE: DDC

Dominion Diamond – Purely Canadian

› Low-risk jurisdiction

› Two of the richest producing diamond mines in the world

• Ekati Diamond Mine – 88.9% ownership of the Core Zone and 65.3% of the Buffer Zone

• Diavik Diamond Mine – 40% ownership

› Ekati Diamond Mine has large-scale development assets including the Jay pipe

› Experienced management team based in the Northwest Territories

› Strong Balance Sheet to fund Capex and Environmental Bonds with $458 million of unrestricted cash and $45 million of debt (as of January 31, 2015)

› Dividend declared on April 8, 2015 of 40 cents per share to be paid in full on May 21, 2015 to shareholders of record as of April 30, 2015

• Subject to declaration by the Board of Directors, the Company intends to pay a regular annual dividend of 40 cents per share in total to be paid semi-annually through an interim and final dividend. For fiscal 2016 an interim dividend of $0.20 per share is expected to be paid in or around November 2015, and the final dividend is expected to be paid in or around May 2016

The only major diamond producer operating exclusively in Canada

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TSX/NYSE: DDC

Dominion Diamond – Purely Canadian

Consistent Diamond Production in a Politically Stable Environment

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TSX/NYSE: DDC

Our Assets 5

Diavik

Ekati

Jay

Sable

Misery

Fox

Lynx

Beartooth

Koala North

Koala U/G

Panda

Pigeon

A-154NA-154S

A-418

A-21

Looking South

Looking South

TSX/NYSE: DDC

Why did we buy Ekati?

Initial Purchase April 2013 $553 million

Ekati Working Capital

› Rough Diamond Inventories $154 million

› Cash $62 million

› Mine supplies $165 million

Purchase price net of WC $172 million

FY15 Segment Operating Profit $125 million

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Current Ownership1

88.9% Core Zone 20.2M carats of Reserves

51.4M carats of Indicated Resources

65.3% Buffer Zone 85.6M carats of Reserves

91.6M carats of Indicated Resources

1 Reserves and Resources are as of January 31, 2015, and on a 100% basis; Mineral resources are inclusive of Mineral Reserves.

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Ekati – Already Delivering Improvements

Plant Improvements Completed:

› Heavy Media Separators added (HMS)› Systematic Screen Monitoring and

Replacement› X-Ray Recovery improved

Additional planned improvements:

› High Pressure Grinding Rolls added (HPGR)› More HMS › More Grease Tables› Installed re-crush capability

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Carats recovered for FY15 were approximately 28% ahead of plan

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Ekati - Misery Main and Satellite Pipes 8

Misery Main

› Probable Reserve increased grade from 4.0carats per tonne to 4.7 carats per tonne

› 3.0 million tonnes of probable reserves

› Approximate price per carat of US$861

Satellites – South and Southwest Extension

› FY 2015: 805,000 carats recovered; grade of1.39 carats per tonne, average price of $78per carat

Capex

› Approximately $70 million in fiscal 2016 and$38 million at the beginning of fiscal 2017remains to be spent before the first ore fromMisery Main is anticipated to be put throughthe processing plant in early calendar 2016

1 Based on the Company’s October 2014 prices.

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Ekati – Pigeon Pipe 9

› Located 5km northwest of Koala with asurface area of 3.5 hectares

› Stripping of waste material alreadyunderway

› Ore mining scheduled to commence incalendar 2015 and finishing in 2019

› 3.6 million carats in Probable Mineral

Reserve

› 5.9 million carats of Indicated MineralResources

› Approximate price per carat of US$1801

1 Based on the Company’s October 2014 prices.Mineral resources that are not mineral reserves do not have demonstrated economic viability; Mineral resources are inclusive of Mineral reserves.

The Pigeon Pipe just before de-watering commenced

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Ekati - Jay Pipe 10

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› Located 7km from the existing Misery pit and

approximately 30km from the Ekati process plant

› Jay is the most significant undeveloped deposit

at Ekati and has the potential to extend the mine

life approximately 11 years beyond the current

projected closure in calendar year 2020

› 84.6 million carats were promoted to

Probable Mineral Reserve

› 90.6 million carats of Indicated Mineral

Resources

› Jay pipe is currently undergoing permitting. A

ministerial decision regarding the Environmental

Assessment is expected in late calendar 2015.

Once this decision is issued, the water and land-

use permitting process will take a further six to

eight months

› Production planned to begin in 2020, ramping up

to full production in 2021 and finishing in 2031

Mineral resources that are not mineral reserves do not have demonstrated economic viability; Mineral resources are inclusive of Mineral reserves.

TSX/NYSE: DDCJay Pre-Feasibility Study Results –Financial and Project Highlights

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Note: All US$ figures refer to unescalated 2014 United States Dollars and are on a 100% basis. All tonne totals refer to dry metric tonnes.1. This estimate is at an assumed exchange rate of 1.135 CA$/US$ in calendar 2015 and 1.10 CA$/US$ in calendar 2016 and thereafter, and includes a

US$83M contingency. The primary capital development cost is expected to be the construction of the dike and its associated infrastructure, includingroads and pumping infrastructure.

2. Using the average prices from the Company's calendar 2014 rough diamond sales and the current diamond recovery profile of the Ekati processing plant,the Company has modeled the diamond price for Jay to be approximately US$64 per carat. Price forecasts for the Jay PFS are inclusive of a real 2.5%annual escalation from the average 2014 price over the life of the mine. The 2.5% price escalation price forecast is based on the Company’s analysis oflong term supply-demand balance in the diamond market.

3. After taxes/royalties and unleveraged. Taxes are calculated on a stand-alone basis. Key applicable taxes assumed include a 13% Northwest Territoriesroyalty rate and a 26.5% statutory income tax rate.

4. Operating costs estimated at a diesel fuel price of $1.20/litre delivered to Ekati.

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Ekati OverviewRoad

System

Dike

Pit

Mined waste 182.1 million tonnes

Mined ore 45.6 million tonnes

Strip ratio 3.99

Recovered carats 84.6 million carats

Recovered grade 1.9 carats per tonne

Initial development capital US$657 million1

Pre-stripping capital US$33 million1

Sustaining capital US$148 million1

Average diamond price US$86 per carat2

Pre-tax NPV US$1,127 million

Post-tax NPV US$610 million3

Real discount rate 7%

Mine operational life 11 years

Average total operating cost per tonne processed

$75 per tonne4

Pre-tax IRR 21%

Post-tax IRR 16%3

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Ekati – The Future

In the current Mine Plan

› Misery Main push back on plan

› Pigeon permitted and on plan

› Lynx permitted and on plan

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Other

› Sable – Open Pit

› Permitted for mining and haulage road permitting in progress

› Bulk sample completed in April 2015. Plans are to complete a pre-feasibility study

› Jay – Open Pit

› Developers Assessment Report (DAR) filed in November 2014

› Pre-feasibility study results announced in January 2015

Longer-term exploration potential

› Fox underground

› Jay underground

› Exploration potential on existing trend lines

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Diavik Diamond Mine 13

› 53 million carats in total Reserves(proven and probable)

› 10 million carats at the A-21 pipe waspromoted to proven reserves

› A-21 development approved by theoperator in November 2014

› The Company’s 40% share ofdevelopment capital is estimated to beCDN$157 million

› Construction is expected to commence in2015 and diamond production anticipatedby the end of 2018

› The timing of A-21 in the mine plan doesnot extend the existing mine life but addsadditional feed to the process plant whenthe A-154S pipe is depleted