The club's pre-tax loss more than doubled from £20.8m the season before as the club spent big on realising its Premier League dream.
The main increase was via player wages and staff salaries which soared from £24.8m to £44.6m.
However the £55m figure is believed to be inflated by around £20m on promotion bonuses for staff and players, plus extra transfer fees owed as a result of promotion.
Wolves signed Ruben Neves (£15.8m), Roderick Miranda (£2.5m), Rafa Mir (£1.5m) and Barry Douglas (£1m) during the season, which ended with them winning promotion as champions.
Average attendances were way up, from 21,572 in 2016/17 to 28,298 as fans flocked to watch their team storm the Championship.
That resulted in ticket income rising £1.3m, up to £7.8m.
The huge level of loss overall was more than double that of its turnover which rose from £23.7m to £26.4m for Fosun-owned club.
Revenue was boosted by a £600,000 rise in merchandising and £400,000 from corporate hospitality.
Promotion to the Premier League will significantly boost Wolves' income for the current financial year – they'll generate around £100m in television money alone, while ticket, corporate and sponsorship figures will dramatically increase.
The club has already spent a whopping £109m on players this season but club bosses are confident of remaining within Financial Fair Play rules.
Wolves are currently seventh in the Premier League and in the quarter finals of the FA Cup.
Sponsorship and advertising income for the 2017/18 year was down from £3.8m to £2.6m.
Wolves playing staff increased from 74 in May 2017 to 89 with non-playing staff numbers rising from 208 to 230.
Staff costs increased from £28.2m for the previous year to £50.7m with wages and salaries up from £24.8m to £44.6m.
The amount that is owed to immediate parent company W W (1990) rose from £59.5m at the end of 2016-2017 to £107.5m at the end of 2017-2018.