Mills was the longstanding chair of the All Party Parliamentary Group on Unconventional Oil and Gas  until May 2017. The APPG was not re-formed after the June general election.
'Shale gas is a great opportunity'
In 2014, Mills participated in the UK Shale Gas World Congress, a planning and strategy summit of oil and gas industrialists. In an interview with Shale World, he said:
- 'I think shale gas is a great opportunity to provide the UK with a domestic energy supply -this is especially important as production of gas in the North Sea declines. It is important for the UK to find a domestic energy source, as this will ease our dependence on unpredictable foreign sources of energy and enable us to have greater control of energy prices'.
- 'What we want is to see a lot of companies involved in the shale industry in the UK with good experience – as with those operating in the North Sea.'
- 'I would say that the industry is moving forward, yes. Cuadrilla has demonstrated, and continues to show that it is committed to maximising explorations and the Government has shown support for this. We need to move forward slowly and steadily, making sure the regulation works, the safety works and then hopefully in the near future we can see this industry making an impact on the UK’s energy security'. 
Mills wrote a case supporting fracking in PoliticsHome in March 2015, saying:
'I find that environmental campaigners tend to ignore the importance of gas here in the UK and in their homes – they continue to use gas to heat their homes whilst questioning the potential at this premature stage, without providing any sort of alternative. They also tend to ignore the environmental and economic benefits and the experts’ advice – that properly regulated shale production is safe.'
'What I would say to these people is, can we really afford to pass this up, especially when the experts consistently agree that, properly regulated, shale has real potential?' 
He served as chair of the All Party Parliamentary Group on Unconventional Oil and Gas from May 2015- June 2017.
Mill's constituency includes one oil and gas licence block, awarded to INEOS by the Oil and Gas Authority under the 14th licensing round in 2015. There are plans for one shale well and 2D and 3D seismic surveying, but no active applications were underway in November 2016.  In August 2015, INEOS announced plans to start test-drilling in this block in 2016 or 2017, with the possibility of 'early stages of producing commercial gas by the end of the decade'.  In May 2016, INEOS held an invitation-only meeting to town and parish council representatives for Amber Valley and Derbyshire. 
Mills has generally voted against increased regulation on fracking. 
- 26 January 2015: voted against making fracking companies apply for an environmental permit before conducting exploratory drilling. He voted against an amendment to the Infrastructure Bill to include an 18-month moratorium on fracking.
- 11 February 2015: voted in favour of requiring more pre-conditions for where fracking can take place.
- 16 December 2015: voted in favour of weakening regulations on fracking in protected areas and national parks.
- Chair since 2015 of the All Party Parliamentary Group on Unconventional Oil and Gas, set up 2013
- Secretary of the All-Party Parliamentary Group for Food and Drink Manufacturing
- Vice-chair of the Associate Parliamentary Group on Business, Finance and Accountancy 
- Nigel Mills, UK Parliament, 10 September 2013.
- Nigel Mills Express, accessed 18 May 2015
- Register Of All-Party Parliamentary Groups [as at 3 February 2016, Parliament.uk, accessed 16 December 2016.
- Melissa Jones, Fracking parliamentary groups hang up their hard hats, Spinwatch, 5 October 2017
- Cristina, Is the UK shale gas industry moving forward? Nigel Mills, MP, Amber Valley county council, Shale World, 31 March 2014, accessed 16 December 2016.
- Norman Baker and Nigel Mills, Debate: Is fracking the answer on energy security?, PoliticsHome, 19 March 2015, accessed 16 December 2016.
- Oil and gas: licensing rounds, GOV.uk, accessed 14 November 2016.
- Fracking tests could happen in Derbyshire in 2016, Derby Telegraph, 19 August 2015, accessed 16 December 2016.
- Clare Washbrook, Amber Valley protests fracking, Nailed, 10 May 2016, accessed 16 December 2016.
- TheyWorkForYou | Nigel Mills, TheyWorkForYou, accessed 16 December 2016.
- Food and Drink APPG,www.parliament.uk, accessed 18 November 2015
- Business, Finance and Accountancy APPG Register Feb 16, www.parliament.uk, accessed 19 February 2016