This study investigates whether the upward trend in real energy prices since the 1990s can account for the decreasing trend in real interest rates in energy-importing countries. By estimating dynamic panel data models, I first provide empirical evidence that a rise in real energy prices leads to falls in real interest rates and aggregate consumption in energy-importing OECD member countries. Using a life-cycle model, I show that the increasing trend in real energy prices decreased the equilibrium real interest rate by about 1.4 percentage points between 1990 and 2018. The mechanism for this effect is as follows: As a result of the increases in the real energy price, energy consumption falls, dampening the consumption of manufactured goods because of the complementarity in consumption between energy and manufactured goods. Accordingly, aggregate consumption declines, putting downward pressure on the real interest rate. Moreover, the increased real energy price decreases energy input in production, raising the capital/energy ratio and inducing a lower real interest rate via a fall in the marginal product of capital. Through a simulation, I also demonstrate that increases in the real energy price had a greater influence on the declining real interest rate in energy-importing countries during 1990–2018, compared to population aging.