Maryland Route 158 is a state highway located in Baltimore County in the U.S. state of Maryland. Known as Bethlehem Boulevard, the state highway runs 2.35 miles (3.78 km) from Riverside Drive in Sparrows Point east to North Point Road in Edgemere. MD 158 parallels Interstate 695 (I-695) along the northern edge of the former Bethlehem Steel complex at Sparrows Point and connects MD 157 with MD 151. Bethlehem Boulevard was constructed as a four-lane divided county highway with several interchanges in the late 1950s. The highway was designated MD 158 in the early 1990s. When I-695 was completely rebuilt and expanded from two to four lanes through Sparrows Point and Edgemere in the late 1990s, MD 158 was also reconstructed as a mostly two-lane highway without interchanges.

Interstate 695 (I-695) is a 51.46-mile-long (82.82 km) auxiliary Interstate Highway that constitutes a beltway extending around Baltimore, Maryland, United States. I-695 is officially designated the McKeldin Beltway but is colloquially referred to as either the Baltimore Beltway or 695. The route is an auxiliary route of I-95, intersecting that route southwest of Baltimore near Arbutus and northeast of the city near White Marsh. It also intersects other major roads radiating from the Baltimore area, including I-97 near Glen Burnie, the Baltimore–Washington Parkway near Linthicum, I-70 near Woodlawn, I-795 near Pikesville, and I-83 in the Timonium area. The 19.37-mile (31.17 km) portion of the Baltimore Beltway between I-95 northeast of Baltimore and I-97 south of Baltimore is officially Maryland Route 695 (MD 695) and is not part of the Interstate Highway System but is signed as I-695. The Francis Scott Key Bridge that crossed over the Patapsco River was included in this section of the route before the bridge's collapse on March 26, 2024. The bridge and its approaches were maintained by the Maryland Transportation Authority (MDTA), while the remainder of the Baltimore Beltway is maintained by the Maryland State Highway Administration (MDSHA).